Saccharopine lysine catabolism pathway. The saccharopine pathway is the most prominent pathway for the catabolism of lysine. Like all amino acids, catabolism of lysine is initiated from the uptake of dietary lysine or from the breakdown of intracellular protein. Catabolism is also used as a means to control the intracellular concentration of free lysine and maintain a steady-state to prevent the toxic effects of excessive free lysine.
|
|
Catabolism is the metabolic reaction which cells undergo to break down larger molecules, extracting energy. There are two major metabolic pathways of monosaccharide catabolism: glycolysis and the citric acid cycle. In glycolysis, oligo- and polysaccharides are cleaved first to smaller monosaccharides by enzymes called glycoside hydrolases. The monosaccharide units can then enter into monosaccharide catabolism.
|
|
Dopamine catabolism leads to the production of homovanillic acid (HVA).
|
|
One example is the subclass of proteolytic enzymes called oligopeptidase. The amino acids produced by catabolism may be directly recycled to form new proteins, converted into different amino acids, or can undergo amino acid catabolism to be converted to other compounds via the Krebs cycle.
|
|
The fact that JH diol phosphate is a significant metabolite Halarnkar, P.P., Jackson, G.P., Straub, K.M., Schooley, D.A., 1993. Juvenile hormone catabolism in Manduca sexta - homologue selectivity of catabolism and identification of a diol-phosphate conjugate as a major end product. Experientia 49, 988-994 certainly weakens the long-held dogma that JH esterase is most important in JH catabolism. While JHE has been noted to have phosphatase activity, to our knowledge it has never been tested on JH diol phosphate.
|
|
Catabolism of fatty acids also produces energy in the form of ATP that is necessary for the gluconeogenesis pathway.
|
|
The term amphibolic ()Chambers Dictionary,11th edition; Liddell & Scott lexicon, 1963 is used to describe a biochemical pathway that involves both catabolism and anabolism. Catabolism is a degradative phase of metabolism in which large molecules are converted into smaller and simpler molecules, which involves two types of reactions. First, hydrolysis reactions, in which catabolism is the breaking apart of molecules into smaller molecules to release energy. Examples of catabolic reactions are digestion and cellular respiration, where sugars and fats are broken down for energy.
|
|
Anabolism operates with separate enzymes from catalysis, which undergo irreversible steps at some point in their pathways. This allows the cell to regulate the rate of production and prevent an infinite loop, also known as a futile cycle, from forming with catabolism. The balance between anabolism and catabolism is sensitive to ADP and ATP, otherwise known as the energy charge of the cell. High amounts of ATP cause cells to favor the anabolic pathway and slow catabolic activity, while excess ADP slows anabolism and favors catabolism.
|
|
In molecular biology, protein catabolism is the breakdown of proteins into amino acids and simple derivative compounds, for transport into the cell through the plasma membrane and ultimately for the polymerization into new proteins via the use of ribonucleic acids (RNA) and ribosomes. Protein catabolism, which is the breakdown of macromolecules, is essentially a digestion process. Protein catabolism is most commonly carried out by non- specific endo- and exo-proteases. However, specific proteases are used for cleaving of proteins for regulatory and protein trafficking purposes.
|
|
Humans, animals, bacteria and plants contain several types of carboxypeptidases that have diverse functions ranging from catabolism to protein maturation.
|
|
Juvenile hormone catabolism in Manduca sexta - homologue selectivity of catabolism and identification of a diol- phosphate conjugate as a major end product. Experientia 49, 988-994 Maxwell et al.Maxwell, R.A., Welch, W.H., Schooley, D.A., 2002. JH diol kinase: part I-Purification, characterization and substrate specificity of juvenile hormone selective diol kinase from Manduca sexta.
|
|
The conjugate (10S,11S) JH diol phosphate is the product of a two-step enzymatic process: conversion of JH to JH diol and then addition of a phosphate group to C10.Halarnkar, P.P., Jackson, G.P., Straub, K.M., Schooley, D.A., 1993. Juvenile hormone catabolism in Manduca sexta - homologue selectivity of catabolism and identification of a diol-phosphate conjugate as a major end product. Experientia 49, 988-994Reversed-phase liquid chromatographic separation of juvenile hormone and its metabolites, and its application for an in vivo juvenile hormone catabolism study in Manduca sexta. Anal. Biochem.
|
|
The word catabolism is from New Latin, which got the roots from Greek: κάτω kato, "downward" and βάλλειν ballein, "to throw".
|
|
This nucleotide is used to transfer chemical energy between different chemical reactions. There is only a small amount of ATP in cells, but as it is continuously regenerated, the human body can use about its own weight in ATP per day. ATP acts as a bridge between catabolism and anabolism. Catabolism breaks down molecules, and anabolism puts them together.
|
|
These are broadly classified as plant-derived fructooligosaccharides or dairy-derived galactooligosaccharides, which are differentially metabolized and distinct from milk oligosaccharide catabolism.
|
|
Schematical diagram Catabolism () is the set of metabolic pathways that breaks down molecules into smaller units that are either oxidized to release energy or used in other anabolic reactions. Catabolism breaks down large molecules (such as polysaccharides, lipids, nucleic acids, and proteins) into smaller units (such as monosaccharides, fatty acids, nucleotides, and amino acids, respectively). Catabolism is the breaking-down aspect of metabolism, whereas anabolism is the building-up aspect. Cells use the monomers released from breaking down polymers to either construct new polymer molecules or degrade the monomers further to simple waste products, releasing energy.
|
|
These all contribute to the overall reaction to detoxify the bacteria from harmful propionyl-CoA. It is also attributed as a resulting pathway due to the catabolism of fatty acids in mycobacteria. In order to proceed, the prpC gene codes for methylcitrate synthase, and if not present, the methylcitrate cycle will not occur. Instead, catabolism proceeds through propionyl-CoA carboxylase.
|
|
HMOX1 (heme oxygenase (decycling) 1) is a human gene that encodes for the enzyme heme oxygenase 1 (). Heme oxygenase mediates the first step of heme catabolism, it cleaves heme to form biliverdin. Heme oxygenase, an essential enzyme in heme catabolism, cleaves heme to form biliverdin, carbon monoxide, and ferrous iron. The biliverdin is subsequently converted to bilirubin by biliverdin reductase.
|
|
Xylanase catalyzes the catabolism of xylan into xylose. Given that plants contain a lot of xylan, xylanase is thus important to the nutrient cycle.
|
|
Thus, mammalian placenta, due to intensive tryptophan catabolism has the ability to suppress T cell activity, thereby contributing to its position of immunologically privileged tissue.
|
|
5-Formiminotetrahydrofolate is an intermediate in the catabolism of histidine. It is produced by glutamate formimidoyltransferase and then converted into 5,10-methenyltetrahydrofolate by formiminotransferase cyclodeaminase.
|
|
Absorptive state is the period in which the gastrointestinal tract is full and the anabolic processes exceed catabolism. The fuel used for this process is glucose.
|
|
3-hydroxyisobutyrate dehydrogenase is a tetrameric mitochondrial enzyme that catalyzes the NAD+-dependent, reversible oxidation of 3-hydroxyisobutyrate, an intermediate of valine catabolism, to methylmalonate semialdehyde.
|
|
Like other antibody-based medications, which are made of amino acid chains called polypeptides, emapalumab is broken down into smaller peptides via the body's normal catabolism.
|
|
N′-Formylkynurenine is an intermediate in the catabolism of tryptophan. It is a formylated derivative of kynurenine. The formation of N′-formylkynurenine is catalyzed by heme dioxygenases.
|
|
The initial catabolism of fructose is sometimes referred to as fructolysis, in analogy with glycolysis, the catabolism of glucose. In fructolysis, the enzyme fructokinase initially produces fructose 1-phosphate, which is split by aldolase B to produce the trioses dihydroxyacetone phosphate (DHAP) and glyceraldehyde . Unlike glycolysis, in fructolysis the triose glyceraldehyde lacks a phosphate group. A third enzyme, triokinase, is therefore required to phosphorylate glyceraldehyde, producing glyceraldehyde 3-phosphate.
|
|
ENTPD6 is similar to E-type nucleotidases (NTPases). NTPases, such as CD39, mediate catabolism of extracellular nucleotides. ENTPD6 contains 4 apyrase-conserved regions which is characteristic of NTPases.
|
|
Catabolism of cardiolipin may happen by the catalysis of phospholipase A2 (PLA) to remove fatty acyl groups. Phospholipase D (PLD) in the mitochondrion hydrolyses cardiolipin to phosphatidic acid.
|
|
Protein catabolism is the process by which proteins are broken down to their amino acids. This is also called proteolysis and can be followed by further amino acid degradation.
|
|
Human blood and urine contain these plus organic acid degradation products of amino acids, neurotransmitters, and intestinal bacterial action on food components. Examples of these categories are alpha-ketoisocaproic, vanilmandelic, and D-lactic acids, derived from catabolism of L-leucine and epinephrine (adrenaline) by human tissues and catabolism of dietary carbohydrate by intestinal bacteria, respectively. The general structure of a few weak organic acids. From left to right: phenol, enol, alcohol, thiol.
|
|
The metabolism of a cell achieves this by coupling the spontaneous processes of catabolism to the non-spontaneous processes of anabolism. In thermodynamic terms, metabolism maintains order by creating disorder.
|
|
MMSDH has esterase activity, which is characteristic of the enzymes in the Aldehyde Dehydrogenase family. It is more specifically involved in the valine and thymine catabolism pathways. When the enzyme acts on valine, (S)-3-hydroxyisobutyric acid is generated as an intermediate; this then undergoes oxidation by the enzyme 3-hydroxyisobutyrate dehydrogenase to form (S)-methylmalonic semialdehyde (MMSA). In thymine catabolism, the enzymatic reaction produces (R)-aminoisobutyric acid (AIBA), which is then deaminated to (R)-methylmalonic semialdehyde.
|
|
This is due in large part to the formation 5,10-methylenetetrahydrofolate, which is one of the few C1 donors in biosynthesis. In this case the methyl group derived from the catabolism of glycine can be transferred to other key molecules such as purines and methionine. Glycine and serine catabolism in and out of the mitochondria. Inside the mitochondria, the glycine cleavage systems links to the serine hydroxymethyltransferase in a reversible process allowing for flux control in the cell.
|
|
These operons contain a number of genes involved in uptake and catabolism of non-favoured carbon sources. During overexpression of Spot 42 sixteen different genes show 2-fold elevated levels of mRNA. The identified genes are mostly involved in central and secondary metabolism, as well as uptake and catabolism of non-preferred carbon sources and oxidation of NADH. A comparative genomics approach was able to broaden the link of Spot 42 with the Escherichia coli TCA cycle.
|
|
If the body had no mechanism for catabolizing the alcohols, they would build up in the body and become toxic. This could be an evolutionary rationale for alcohol catabolism also by sulfotransferase.
|
|
Hemorphin-4 also has inhibitory effects on angiotensin-converting enzyme (ACE), and as a result, may play a role in the regulation of blood pressure. Notably, inhibition of ACE also reduces enkephalin catabolism.
|
|
Maleamate amidohydrolase (, NicF) is an enzyme with systematic name maleamate amidohydrolase. This enzyme catalyses the following chemical reaction : maleamate + H2O \rightleftharpoons maleate + NH3 The reaction is involved in the aerobic catabolism of nicotinic acid.
|
|
The metabolism of pertuzumab has not been directly studied; in general antibodies are cleared principally by catabolism. The median clearance of pertuzumab was 0.235 liters/day and the median half- life was 18 days.
|
|
Fumarylacetoacetase is an enzyme that in humans is encoded by the FAH gene located on chromosome 15. The FAH gene is thought to be involved in the catabolism of the amino acid phenylalanine in humans.
|
|
It also recognizes both JH diol enantiomers, indicating that the absolute stereospecificity of the hydroxy groups is of minor importance. Most surprising is the enzyme's inability to recognize JH acid diols. Because JH acid diol cannot be phosphorylated by JHDK, the generally accepted pathway for JH catabolism (JH acid is converted to JH acid diol) must be reconsidered. Still, the role of cellular JHE becomes problematic if the pathway catalyzed by JHEH and JHDK is the major pathway for JH catabolism in the cell.
|
|
Transamination to phenylpyruvate, whose metabolites are excreted in the urine, represents another pathway of phenylalanine turnover, but catabolism through PAH predominates. In humans, this enzyme is expressed both in the liver and the kidney, and there is some indication that it may be differentially regulated in these tissues. PAH is unusual among the aromatic amino acid hydroxylases for its involvement in catabolism; tyrosine and tryptophan hydroxylases, on the other hand, are primarily expressed in the central nervous system and catalyze rate-limiting steps in neurotransmitter/hormone biosynthesis.
|
|
Cellular wastes include lactic acid, acetic acid, carbon dioxide, ammonia, and urea. The creation of these wastes is usually an oxidation process involving a release of chemical free energy, some of which is lost as heat, but the rest of which is used to drive the synthesis of adenosine triphosphate (ATP). This molecule acts as a way for the cell to transfer the energy released by catabolism to the energy-requiring reactions that make up anabolism. (Catabolism is seen as destructive metabolism and anabolism as constructive metabolism).
|
|
Hemopexin (Hx) is another plasma glycoprotein, like hemoglobin, that is able to bind heme with high affinity. Hemopexin sequesters heme in an inert, non-toxic form and transports it to the liver for catabolism and excretion.
|
|
Bilirubin (BR) is a yellow compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the body's clearance of waste products that arise from the destruction of aged or abnormal red blood cells. First the hemoglobin gets stripped of the heme molecule which thereafter passes through various processes of porphyrin catabolism, depending on the part of the body in which the breakdown occurs. For example, the molecules excreted in the urine differ from those in the feces.
|
|
The species Z. muelleri evolved from terrestrial plants, but adapted to marine life around 140 million years ago during the Cretaceous period. In order to adapt to life in the ocean, the Z. muelleri genome lost/modified several genes which had once helped them survive on land, such as genes for hormone biosynthesis and signaling and cell wall catabolism. Some of the genes that were lost include genes associated with ethylene synthesis and signaling pathways, as well as genes involved in pectin catabolism. Additionally, genes for stomatal differentiation, terpenoid synthesis, and ultraviolet resistance were lost.
|
|
Mutations in ETHE1 gene are thought to cause ethylmalonic encephalopathy, a rare inborn error of metabolism. Patients carrying ETHE1 mutations have been found to exhibit lower activity of ETHE1 and affinity for the ETHE1 substrate. Mouse models of Ethe1 genetic ablation likewise exhibited reduced sulfide dioxygenase catabolism and cranial features of ethylmalonic encephalopathy. Decrease in sulfide dioxygenase activity results in abnormal catabolism of hydrogen sulfide, an gas-phase signaling molecule in the central nervous system, whose accumulation is thought to inhibit cytochrome c oxidase activity in the respiratory chain of the mitochondrion.
|
|
In glycogenolysis, it is the direct product of the reaction in which glycogen phosphorylase cleaves off a molecule of glucose from a greater glycogen structure. A deficiency of muscle glycogen phosphorylase is known as glycogen storage disease type V (McArdle Disease). To be utilized in cellular catabolism it must first be converted to glucose 6-phosphate by the enzyme phosphoglucomutase. One reason that cells form glucose 1-phosphate instead of glucose during glycogen breakdown is that the very polar phosphorylated glucose cannot leave the cell membrane and so is marked for intracellular catabolism.
|
|
N-formylmaleamate deformylase (, NicD) is an enzyme with systematic name N-formylmaleamic acid amidohydrolase. This enzyme catalyses the following chemical reaction : N-formylmaleamic acid + H2O \rightleftharpoons maleamate + formate The reaction is involved in the aerobic catabolism of nicotinic acid.
|
|
Sphingolipid metabolism is based in compartmentalization. In this way, possible cycles of opposite anabolism and catabolism reactions are avoid. The ER is the compartment where the synthesis of ceramide is produced. Then, it will move to the Golgi apparatus.
|
|
Another hypothesis regarding the fate of propionyl-CoA, in M. tuberculosisis, is that since propionyl-CoA is produced by beta odd chain fatty acid catabolism, the methylcitrate cycle is activated subsequently to negate any potential toxicity, acting as a buffering mechanism.
|
|
Alpha-pinene monooxygenase () is an enzyme with systematic name (-)-alpha- pinene,NADH:oxygen oxidoreductase. This enzyme catalyses the following chemical reaction : (-)-alpha-pinene + NADH + H+ \+ O2 \rightleftharpoons alpha-pinene oxide + NAD+ \+ H2O Alpha-pinene monooxygenase takes part in catabolism of alpha-pinene.
|
|
In 1950, Ashwell joined the National Institute of Arthritis, Metabolism, and Digestive Diseases.Kresge, Nicole, Robert D. Simoni, and Robert L. Hill. “Hepatic Carbohydrate Binding Proteins and Glycoprotein Catabolism: the Work of Gilbert G. Ashwell.” The Journal of Biological Chemistry. n.d. Web.
|
|
The facultative lagoon may be replaced by an aerated lagoon as the first pond of the series. Aerated lagoons have mechanical aerators which minimize anaerobic zones by completely mixing the lagoon to achieve catabolism through a process called extended aeration.
|
|
The company particularly focuses on niche drugs for small patient populations. Products include the ADHD medicine, Desoxyn (brand name for methamphetamine hydrochloride), and vigabatrin, an anticonvulsant that inhibits the catabolism of GABA and is indicated for epilepsy and substance abuse.
|
|
Steroid hormones are generally carried in the blood, bound to specific carrier proteins such as sex hormone-binding globulin or corticosteroid-binding globulin. Further conversions and catabolism occurs in the liver, in other "peripheral" tissues, and in the target tissues.
|
|
PPT-1 a member of the palmitoyl protein thioesterase family. PPT-1 is a small glycoprotein involved in the catabolism of lipid-modified proteins during lysosomal degradation. This enzyme removes thioester-linked fatty acyl groups such as palmitate from cysteine residues.
|
|
Supplementary "protein substitute" formulas are typically prescribed for people PKU (starting in infancy) to provide the amino acids and other necessary nutrients that would otherwise be lacking in a low-phenylalanine diet. Tyrosine, which is normally derived from phenylalanine and which is necessary for normal brain function, is usually supplemented. Consumption of the protein substitute formulas can actually reduce phenylalanine levels, probably because it stops the process of protein catabolism from releasing Phe stored in the muscles and other tissues into the blood. Many PKU patients have their highest Phe levels after a period of fasting (such as overnight), because fasting triggers catabolism.
|
|
When amino acid catabolism increases, N-Acetylglutamate synthase is up-regulated, producing more N-acetyl-L-glutamate, which up-regulates carbamoyl phosphate synthetase and allows it to dispose of the excess NH4+ from catabolism. Aminoacylase is up- regulated during times of nutrient deficit or starvation, causing N-acetyl-L- glutamate breakdown, which down-regulates carbamoyl phosphate synthetase and the rest of the urea cycle. This response is evolutionarily advantageous, since a nutrient deficit means there isn't as much NH4+ that needs to be disposed of and since the body wants to salvage as many amino acids as it can.
|
|
BTG subsequently won approvals for orphan drug status by the Food and Drug Administration for treating alcoholic hepatitis, Turner syndrome, and HIV-induced weight loss. It is also indicated as an offset to protein catabolism caused by long-term administration of corticosteroids.
|
|
High calcium content and high catabolism for alcohol makes it a favorite anju (side dish for drinking). Makchang gui is said to be originate from Daegu and the surrounding Gyeongsang region. Makchang gui, Maeil News, 2009-12-09. Retrieved 2010-06-25.
|
|
ACAT also plays an important role in foam cell formation and atherosclerosis by participating in accumulating cholesterol esters in macrophages and vascular tissue. The rate-controlling enzyme in cholesterol catabolism, hepatic cholesterol 7-hydroxylase, is believed to be regulated partly by ACAT.
|
|
Biotin is a coenzyme for multiple carboxylase enzymes, which are involved in the digestion of carbohydrates, synthesis of fatty acids, and gluconeogenesis. Biotin is also required for the catabolism and utilization of the three branched-chain amino acids: leucine, isoleucine, and valine.
|
|
PAOs in plants, bacteria and protozoa oxidise spermidine and spermine to an aminobutyral, diaminopropane and hydrogen peroxide and are involved in the catabolism of polyamines. Other members of this family include tryptophan 2-monooxygenase, putrescine oxidase, corticosteroid-binding proteins, and antibacterial glycoproteins.
|
|
Ectonucleoside triphosphate diphosphohydrolase 3 is an enzyme that in humans is encoded by the ENTPD3 gene. ENTPD3 is similar to E-type nucleotidases (NTPases). NTPases, such as CD39, mediate catabolism of extracellular nucleotides. ENTPD3 contains 4 apyrase-conserved regions which is characteristic of NTPases.
|
|
ACAD8 is an isobutyryl-CoA dehydrogenase that functions in the catabolism of branched-chain amino acids including valine, and shows high reactivity toward isobutyryl-CoA. ACAD8 is responsible for the third step in the breakdown of valine and converts isobutyryl-CoA into methylacrylyl-CoA.
|
|
If the amount of plasma protein is decreased (such as in catabolism, malnutrition, liver disease, renal disease), there would also be a higher fraction unbound. Additionally, the quality of the plasma protein may affect how many drug-binding sites there are on the protein.
|
|
Since biotin is present in many foods at low concentrations, deficiency is rare except in locations where malnourishment is very common. Pregnancy, however, alters biotin catabolism and despite a regular biotin intake, half of the pregnant women in the U.S. are marginally biotin deficient.
|
|
Recent studies have shown marginal biotin deficiency can be present in human gestation, as evidenced by increased urinary excretion of 3-hydroxyisovaleric acid, decreased urinary excretion of biotin and bisnorbiotin, and decreased plasma concentration of biotin. Additionally, smoking may further accelerate biotin catabolism in women.
|
|
The conversion of tryptophan to serotonin and other metabolites depends on vitamin B6. If tryptophan catabolism has any impact on brain glutaric acid and other catabolite levels, vitamin B6 levels should be routinely assayed and normalized in the course of the treatment of GA1.
|
|
Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-down aspect. Anabolism is usually synonymous with biosynthesis.
|
|
California Fish and Game Volume 56 133-134. This fish has green blood plasma, the color caused by biliverdin tightly bound in protein complexes.Fang, L. and J. Bada. (1988) A special pattern of haem catabolism in a marine fish, Clinocottus analis, with green blood plasma.
|
|
Since pembrolizumab is cleared from the circulation through non-specific catabolism, no metabolic drug interactions are expected and no studies were done on routes of elimination. The systemic clearance [rate] is about 0.2 L/day and the terminal half-life is about 25 days.
|
|
The primary reason for protein catabolism is so organisms can convert proteins into a form of energy that the body can use. To reuse their proteins, bacteria or soil microorganisms break down their proteins through protein catabolism into their individual amino acids and are used to form bacterial proteins or oxidized for energy. To convert to energy, once the proteins are broken down, they are typically deaminated (removal of an amino group) so that they can be processed into the Krebs/Citric Acid (TCA) Cycle. By proceeding into the Citric Acid Cycle, the original proteins will be converted into usable energy for the organism.
|
|
Glycoside hydrolase family 59 CAZY GH_59 comprises enzymes with only one known activity; galactocerebrosidase (). Globoid cell leukodystrophy (Krabbe disease) is a severe, autosomal recessive disorder that results from deficiency of galactocerebrosidase (GALC) activity. GALC is responsible for the lysosomal catabolism of certain galactolipids, including galactosylceramide and psychosine.
|
|
This gene encodes a member of the 3-oxoacid CoA-transferase gene family. The encoded protein is a homodimeric mitochondrial matrix enzyme that plays a central role in extrahepatic ketone body catabolism by catalyzing the reversible transfer of coenzyme A (CoA) from succinyl-CoA to acetoacetate.
|
|
Ectonucleoside triphosphate diphosphohydrolase 5 is an enzyme that in humans is encoded by the ENTPD5 gene. ENTPD5 is similar to E-type nucleotidases (NTPases)/ecto-ATPase/apyrases. NTPases, such as CD39, mediate catabolism of extracellular nucleotides. ENTPD5 contains 4 apyrase-conserved regions which is characteristic of NTPases.
|
|
Metabolism involves two biochemical processes that occur in living organisms. The first is anabolism, which refers to the build up of molecules. The second is catabolism, the breakdown of molecules. These two processes work to regulate the amount of energy the body uses to maintain itself.
|
|
These opines cannot be utilized by the plant host, and will instead be exported out of the plant cell where it can be taken up by the Agrobacterium cells. The bacteria possess genes in other regions of the Ti plasmid that allows the catabolism of opines.
|
|
Urea and creatinine are nitrogenous end products of metabolism. Urea is the primary metabolite derived from dietary protein and tissue protein turnover. Creatinine is the product of muscle creatine catabolism. Both are relatively small molecules (60 and 113 daltons, respectively) that distribute throughout total body water.
|
|
However, depending on pH and temperature, methanogenesis has been shown to use carbon from other small organic compounds, such as formic acid (formate), methanol, methylamines, tetramethylammonium, dimethyl sulfide, and methanethiol. The catabolism of the methyl compounds is mediated by methyl transferases to give methyl coenzyme M.
|
|
Other enzymes involved in the catabolism of phenylalanine include phenylalanine hydroxylase, aminotransferase, p-hydroxyphenylpyruvate dioxygenase, homogentisate oxidase, and fumarylacetoacetate hydrolase. Mutations in some of these enzymes can lead to more severe diseases such as, phenylketonuria, alkaptonuria, and tyrosinemia. The gene GSTZ1 is located on chromosome 14q24.3.
|
|
Chemotaxis, or the directed movement of motile organisms towards or away from chemicals in the environment is an important physiological response that may contribute to effective catabolism of molecules in the environment. In addition, mechanisms for the intracellular accumulation of aromatic molecules via various transport mechanisms are also important.
|
|
May 8, 2014. ATGL is an enzyme involved in catabolism of triglycerides (long-term fat storage) into fatty acids (short-term fat storage) within the body In the absence of fully functional ATGL, triglycerides accumulate in the bloodstream and bodily tissues. Interestingly, individuals with NLSD are not typically obese.
|
|
Maltose-binding protein (MBP) is a part of the maltose/maltodextrin system of Escherichia coli, which is responsible for the uptake and efficient catabolism of maltodextrins. It is a complex regulatory and transport system involving many proteins and protein complexes. MBP has an approximate molecular mass of 42.5 kilodaltons.
|
|
Aescin appears to produce effects through a wide range of mechanisms. It induces endothelial nitric oxide synthesis by making endothelial cells more permeable to calcium ions, and also induces release of prostaglandin F2α. Other possible mechanisms include serotonin antagonism and histamine antagonism and reduced catabolism of tissue mucopolysaccharides.
|
|
Succinyl CoA can be formed from methylmalonyl CoA through the utilization of deoxyadenosyl-B12 (deoxyadenosylcobalamin) by the enzyme methylmalonyl-CoA mutase. This reaction, which requires vitamin B12 as a cofactor, is important in the catabolism of some branched-chain amino acids as well as odd-chain fatty acids.
|
|
Outer membrane transport proteins (OMPP1/FadL/TodX) family includes several proteins that are involved in toluene catabolism and degradation of aromatic hydrocarbons. This family also includes protein FadL involved in translocation of long-chain fatty acids across the outer membrane. It is also a receptor for the bacteriophage T2.
|
|
The protein is a pyrimidine catabolic enzyme and the initial and rate-limiting factor in the pathway of uracil and thymidine catabolism. Genetic deficiency of this enzyme results in an error in pyrimidine metabolism associated with thymine-uraciluria and an increased risk of toxicity in cancer patients receiving 5-fluorouracil chemotherapy.
|
|
It can form by action of ketolase on fructose 1,6-bisphosphate in an alternate glycolysis pathway. This compound is transferred by thiamine pyrophosphate during the pentose phosphate shunt. In purine catabolism, xanthine is first converted to urate. This is converted to 5-hydroxyisourate, which decarboxylates to allantoin and allantoic acid.
|
|
It is an intermediate in the catabolism of aromatic amino acids such as phenylalanine and tyrosine. p-Hydroxyphenyl pyruvate (produced by transamination of tyrosine) is acted upon by the enzyme p-hydroxyphenyl pyruvate oxidase to yield homogentisate. It is then degraded by the enzyme homogentisate oxidase to give maleyl-acetoacetate.
|
|
Heme oxygenase or haem oxygenase (HO) is an enzyme that catalyzes the degradation of heme. This produces biliverdin, ferrous iron, and carbon monoxide. HO was first described in the late 1960s when Raimo Tenhunen demonstrated an enzymatic reaction for heme catabolism. HO is the premier source for endogenous carbon monoxide (CO) production.
|
|
Sources for β-alanine includes pyrimidine catabolism of cytosine and uracil. β-Alanine can undergo a transamination reaction with pyruvate to form malonate-semialdehyde and L-alanine. The malonate semialdehyde can then be converted into malonate via malonate-semialdehyde dehydrogenase. Malonate is then converted into malonyl-CoA and enter fatty acid biosynthesis.
|
|
Chemolithotrophs belong to the domains Bacteria and Archaea. The term "lithotroph" was created from the Greek terms 'lithos' (rock) and 'troph' (consumer), meaning "eaters of rock". Many but not all lithoautotrophs are extremophiles. Different from a lithotroph is an organotroph, an organism which obtains its reducing agents from the catabolism of organic compounds.
|
|
The intracellular genetic regulatory mechanisms have evolved to enforce this choice, as fermentation provides a faster anabolic growth rate for the yeast cells than the aerobic respiration of glucose, which favors catabolism. After glucose is depleted, the fermentative product ethanol is oxidised in a noticeably slower second growth phase, if oxygen is available.
|
|
It predominantly interacts with A.T residues in ARG boxes. This hexameric protein binds DNA at its N terminus to repress arginine biosynthesis or activate arginine catabolism. Some species have several ArgR paralogs. In a neighbour-joining tree, some of these paralogous sequences show long branches and differ significantly from the well-conserved C-terminal region.
|
|
The half-life of Lp(a) in circulation is approximately three to four days. The mechanism and sites of Lp(a) catabolism are largely unknown. Uptake via the LDL receptor is not a major pathway of Lp(a) metabolism. The kidney has been identified as playing a role in Lp(a) clearance from plasma.
|
|
Most non-autotrophic cells are unable to produce free glucose because they lack expression of glucose-6-phosphatase and, thus, are involved only in glucose uptake and catabolism. Usually produced only in hepatocytes, in fasting conditions, other tissues such as the intestines, muscles, brain, and kidneys are able to produce glucose following activation of gluconeogenesis.
|
|
Abscisic acid (ABA) is a multifunctional plant hormone, playing roles in germination, seasonal growth patterns, and stress response. ABA levels are believed to be regulated in part by control of ABA catabolism, specifically by oxidation to form phaseic acid.Milborrow BV. (1969). "Identification of 'Metabolite C' from abscisic acid and a new structure for phaseic acid".
|
|
Due to difficulty in measuring phenotypes, less is known about the roles of WRKY transcription factors in plant metabolism.Schluttenhofer and Yuan (2014) Regulation of Specialized Metabolism by WRKY Transcription Factors. Plant Physiology. The earliest reports identified WRKYs based on their ability to regulate β-amylase, a gene involved in catabolism of starch into sugars.
|
|
PDE is inherited in an autosomal recessive manner and is estimated to affect around 1 in 400,000 to 700,000 births, though one study conducted in Germany estimated a prevalence of 1 in 20,000 births. The ALDH7A1 gene encodes for the enzyme antiquitin or α -aminoadipic semialdehyde dehydrogenase, which is involved with the catabolism of lysine.
|
|
In molecular biology, the red chlorophyll catabolite reductase (RCC reductase) family of proteins consists of several red chlorophyll catabolite reductase (RCC reductase) proteins. Red chlorophyll catabolite (RCC) reductase (RCCR) and pheophorbide (Pheide) a oxygenase (PaO) catalyse the key reaction of chlorophyll catabolism, porphyrin macrocycle cleavage of Pheide a to a primary fluorescent catabolite (pFCC).
|
|
Antiquitin function and subcellular localization are closely linked, as it functions in detoxification in the cytosol, lysine catabolism in the mitochondrion, and cell cycle progression in the nucleus. In particular, antiquitin localizes to the mitochondria in kidney and liver to contribute to the synthesis of betaine, a chaperone protein that protects against osmotic stress.
|
|
Its phosphate derivatives are involved in many cellular processes. The best-characterized form is thiamine pyrophosphate (TPP), a coenzyme in the catabolism of sugars and amino acids. In yeast, TPP is also required in the first step of alcoholic fermentation. All organisms use thiamine, but it is made only in bacteria, fungi, and plants.
|
|
Sixth ed., p. 506. The ability to harness energy from a variety of metabolic pathways is a property of all living organisms that contains earth science. Growth, development, anabolism and catabolism are some of the central processes in the study of biological organisms, because the role of energy is fundamental to such biological processes.
|
|
Excess uracil competes with 5-FU for DPD, thus inhibiting 5-FU catabolism. The tegafur is taken up by the cancer cells and breaks down into 5-FU, a substance that kills tumor cells. The uracil causes higher amounts of 5-FU to stay inside the cells and kill them. Tegafur is a type of antimetabolite.
|
|
Carbon monoxide is produced in heme catabolism and thus is present in blood. Normal circulating levels in the blood are 0% to 3% saturation, i.e. the ratio of the amount of carboxyhaemoglobin present to the total circulating haemoglobin, and are higher in smokers. Some deep-diving marine mammal species are known to maintain carboxyhemoglobin levels between 5-10%.
|
|
Microbial catabolism of phytosterol side chains yields C-19 steroids, C-22 steroids, and 17-ketosteroids (i.e. precursors to adrenocortical hormones and contraceptives). The addition and modification of functional groups is key when producing the wide variety of medications available within this chemical classification. These modifications are performed using conventional organic synthesis and/or biotransformation techniques.
|
|
Thermococcus members are described as heterotrophic, chemotrophic,Yuusuke Tokooji, T. S., Shinsuke Fujiwara, Tadayuki Imanaka and Haruyuki Atomi (2013). "Genetic Examination of Initial Amino Acid Oxidation and Glutamate Catabolism in the Hyperthermophilic Archaeon Thermococcus kodakarensis." Journal of Bacteriology: 10. and are organotrophic sulfanogens; using elemental sulfur and carbon sources including amino acids, carbohydrates, and organic acids such as pyruvate.
|
|
Various studies have shown that alpha- tocopherol interferes with tocotrienol benefits. High levels of α-tocopherol increase cholesterol production. α-Tocopherol interference with tocotrienol absorption was described previously by scientists, who showed that α-tococopherol interfered with absorption of α-tocotrienol, but not γ-tocotrienol. Finally, α-tocopherol was shown to interfere with tocotrienols by increasing catabolism.
|
|
3,4-dihydroxyphenylalanine reductive deaminase (, reductive deaminase, DOPA- reductive deaminase, DOPARDA) is an enzyme with systematic name 3,4-dihydroxy- L-phenylalanine ammonia-lyase (3,4-dihydroxyphenylpropanoate-forming). This enzyme catalyses the following chemical reaction : L-dopa + 2 NADH \rightleftharpoons 3,4-dihydroxyphenylpropanoate + 2 NAD+ \+ NH3 This enzyme participates in the L-phenylalanine-catabolism in the anaerobic phototrophic bacterium Rhodobacter sphaeroides OU5.
|
|
Inborn errors of carbohydrate metabolism are inborn error of metabolism that affect the catabolism and anabolism of carbohydrates. An example is lactose intolerance. Carbohydrates account for a major portion of the human diet. These carbohydrates are composed of three principal monosaccharides: glucose, fructose and galactose; in addition glycogen is the storage form of carbohydrates in humans.
|
|
Retinoic acid, produced by many cell types, such as nerve cells, dendritic cells, and stromal cells, favours the differentiation of ILC3s, rather than ILC2s, and it is required for their complete maturation. In addition, AhR, which can be triggered through ligands produced after the catabolism food, is required for the maintenance of function and expression of intestinal ILC3s.
|
|
LXR heterodimerises with RXR. Promiscuous RXR also heterodimerises with PPAR members. PPAR-α plays a pivotal role in fatty acid catabolism in liver by upregulating the expression of numerous genes involved in mitochondrial fatty acid oxidation. Thus RXR is a common partner of two nuclear receptors acting in opposite directions with regard to fatty acid metabolism.
|
|
Glycine encephalopathy is a rare autosomal recessive disorder of glycine metabolism. After phenylketonuria, glycine encephalopathy is the second most common disorder of amino acid metabolism. The disease is caused by defects in the glycine cleavage system, an enzyme responsible for glycine catabolism. There are several forms of the disease, with varying severity of symptoms and time of onset.
|
|
N-Acetylanthranilic acid is an organic compound with the molecular formula C9H9NO3. It is an intermediate product in catabolism of quinaldine in Arthrobacter sp., and is further metabolized to anthranilic acid. N-Acetylanthranilic acid can be synthesized from 2-bromoacetanilide via palladium-catalyzed carbonylation in tri-n-butylamine-water at 110-130 °C, under 3 atm of carbon monoxide.
|
|
Catabolism, therefore, provides the chemical energy necessary for the maintenance and growth of cells. Examples of catabolic processes include glycolysis, the citric acid cycle, the breakdown of muscle protein in order to use amino acids as substrates for gluconeogenesis, the breakdown of fat in adipose tissue to fatty acids, and oxidative deamination of neurotransmitters by monoamine oxidase.
|
|
Poly (ADP-ribose) glycohydrolase is an enzyme that in humans is encoded by the PARG gene. Poly (ADP-ribose) glycohydrolase (PARG) is the major enzyme responsible for the catabolism of poly (ADP-ribose), a reversible covalent- modifier of chromosomal proteins. The protein is found in many tissues and may be subject to proteolysis generating smaller, active products.
|
|
Amino acid catabolism results in waste ammonia. All animals need a way to excrete this product. Most aquatic organisms, or ammonotelic organisms, excrete ammonia without converting it. Organisms that cannot easily and safely remove nitrogen as ammonia convert it to a less toxic substance such as urea via the urea cycle, which occurs mainly in the liver.
|
|
The gluconeogenesis pathway is highly endergonic until it is coupled to the hydrolysis of ATP or GTP, effectively making the process exergonic. For example, the pathway leading from pyruvate to glucose-6-phosphate requires 4 molecules of ATP and 2 molecules of GTP to proceed spontaneously. These ATPs are supplied from fatty acid catabolism via beta oxidation.
|
|
This stops respiration by prohibiting reduction of NADH to NAD. This stops biosynthesis of cell membrane products as well as transport and catabolism. Eventually, membrane fluidity and activity of membrane bound enzymes become depleted. It has also been shown to inhibit morphologic change of yeast as well as cell adherence and is directly toxic to yeast.
|
|
FADH2 then reverts to FAD, sending its two high-energy electrons through the electron transport chain; the energy in FADH2 is enough to produce 1.5 equivalents of ATP by oxidative phosphorylation. Some redox flavoproteins non- covalently bind to FAD like Acetyl-CoA-dehydrogenases which are involved in beta-oxidation of fatty acids and catabolism of amino acids like leucine (isovaleryl-CoA dehydrogenase), isoleucine, (short/branched-chain acyl-CoA dehydrogenase), valine (isobutyryl-CoA dehydrogenase), and lysine (glutaryl- CoA dehydrogenase). Additional examples of FAD-dependent enzymes that regulate metabolism are glycerol-3-phosphate dehydrogenase (triglyceride synthesis) and xanthine oxidase involved in purine nucleotide catabolism. Noncatalytic functions that FAD can play in flavoproteins include as structural roles, or involved in blue-sensitive light photoreceptors that regulate biological clocks and development, generation of light in bioluminescent bacteria.
|
|
Hydroxysteroid 17-beta dehydrogenase 6 is an enzyme that in humans is encoded by the HSD17B6 gene. The protein encoded by this gene has both oxidoreductase and epimerase activities and is involved in androgen catabolism. The oxidoreductase activity can convert 3 alpha-adiol to dihydrotestosterone, while the epimerase activity can convert androsterone to epi-androsterone. Both reactions use NAD+ as the preferred cofactor.
|
|
Bilirubin is created by the activity of biliverdin reductase on biliverdin, a green tetrapyrrolic bile pigment that is also a product of heme catabolism. Bilirubin, when oxidized, reverts to become biliverdin once again. This cycle, in addition to the demonstration of the potent antioxidant activity of bilirubin, has led to the hypothesis that bilirubin's main physiologic role is as a cellular antioxidant.
|
|
Like other branched- chain amino acids, the catabolism of valine starts with the removal of the amino group by transamination, giving alpha-ketoisovalerate, an alpha-keto acid, which is converted to isobutyryl-CoA through oxidative decarboxylation by the branched-chain α-ketoacid dehydrogenase complex. This is further oxidised and rearranged to succinyl-CoA, which can enter the citric acid cycle.
|
|
Glycerate kinase is an enzyme that catalyzes the conversion of D-glyceric acid (a.k.a. D-glycerate) to 2-phosphoglycerate. This conversion is an intermediary reaction found in several metabolic pathways, including the degradation (break-down; catabolism) of serine, as well as the breakdown of fructose. A deficiency in glycerate kinase activity leads to the accumulation of D-glyceric acid (a.k.a.
|
|
CMP-Neu5Ac is then transported to the endoplasmic reticulum or the Golgi apparatus, where it can be transferred to an oligosaccharide chain, becoming a new glycoconjugate. This bond can be modified by O-acetylation or O-methylation. When the glycoconjugate is mature it is transported to the cell surface. The sialidase is one of the most important enzymes of the sialic acid catabolism.
|
|
C. atrox Like most other American pit vipers, the venom contains proteolytic enzymes. Proteolytic venoms are concentrated secretions that destroy tissues as a result of catabolism of structural and other proteins, which help in disabling prey. The venom of C. atrox is primarily hemotoxic, affecting mainly the blood vessels, blood cells and the heart. The venom contains hemorrhagic components called zinc metalloproteinases.
|
|
In pure cultures of atrazine-degrading bacteria, as well as active soil communities, atrazine ring nitrogen, but not carbon are assimilated into microbial biomass. Low concentrations of glucose can decrease the bioavailability, whereas higher concentrations promote the catabolism of atrazine. The genes for enzymes AtzA-C have been found to be highly conserved in atrazine-degrading organisms worldwide. In Pseudomonas sp.
|
|
ADP, the Atz genes are located noncontiguously on a plasmid with the genes for mercury catabolism. AtzA-C genes have also been found in a Gram-positive bacterium, but are chromosomally located. The insertion elements flanking each gene suggest that they are involved in the assembly of this specialized catabolic pathway. Two options exist for degradation of atrazine using microbes, bioaugmentation or biostimulation.
|
|
It is a product of the catabolism of protein. It is converted to the less toxic substance urea prior to excretion in urine by the kidneys. The metabolic pathways that synthesize urea involve reactions that start in the mitochondria and then move into the cytosol. The process is known as the urea cycle, which comprises several enzymes acting in sequence.
|
|
A diet that is low in phenylalanine but does not include protein substitutes may also fail to lower blood Phe levels, since a nutritionally insufficient diet may also trigger catabolism. For all these reasons, the prescription formula is an important part of the treatment for patients with classic PKU. Tentative evidence supports dietary supplementation with large neutral amino acids (LNAAs). The LNAAs (e.g.
|
|
The work was the first demonstration that carbohydrate oxidation and carbohydrate phosphorylation were linked, i.e. the two pathways were directly “coupled.” Singleton, R. Jr. 2007b Furthermore, the study helped establish the basic phenomenon of oxidative phosphorylation, opened the way for its systematic exploration, and suggested for the first time that phosphate compounds acted as a link between catabolism and anabolism.
|
|
Isobutyryl-coenzyme A is a starting material for many natural products derived from Poly-Ketide Synthase (PKS) assembly lines, as well as PKS-NRPS hybrid assembly lines. These products can often be used as antibiotics. Notably, it is also an intermediate in the metabolism of the amino acid Valine, and structurally similar to intermediates in the catabolism of other small amino acids.
|
|
It may form from 3-aminoacetone, which is an intermediate of threonine catabolism, as well as through lipid peroxidation. However, the most important source is glycolysis. Here, methylglyoxal arises from nonenzymatic phosphate elimination from glyceraldehyde phosphate and dihydroxyacetone phosphate (DHAP), two intermediates of glycolysis. This conversion is the basis of a potential biotechnological route to the commodity chemical 1,2-propanediol.
|
|
There are many signals that control catabolism. Most of the known signals are hormones and the molecules involved in metabolism itself. Endocrinologists have traditionally classified many of the hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The so-called classic catabolic hormones known since the early 20th century are cortisol, glucagon, and adrenaline (and other catecholamines).
|
|
It is likely that there exists an alternate nonenzymatic bypass that allows the catabolism of 4-maleylacetoacetate in the absence of 4-maleylacetoacetate isomerase. Because of this mechanism, a mutation in the gene encoding 4-Maleylacetoacetate isomerase is not considered dangerous. GSTZ1 is highly expressed in the liver, however mutations in this gene do not impair liver function or coagulation.
|
|
Nitisinone Nitisinone is prescribed ultimately to reduce the accumulation of toxic metabolic intermediates, such as succinylacetate, which are toxic to cells. It modifies the function of 4-hydrooxyphenylpyruvate dioxygenase by acting as a competitive inhibitor. 4-hydrooxyphenylpyruvate dioxygenase functions to convert 4-hydroxyphenylpyruvate to homogentisate as the second enzymatic reaction in the tyrosine catabolic pathway. This prevents the further catabolism of tyrosine.
|
|
Infantile Refsum disease (IRD), is a rare autosomal recessive congenital peroxisomal biogenesis disorder within the Zellweger spectrum. These are disorders of the peroxisomes that are clinically similar to Zellweger syndrome and associated with mutations in the PEX family of genes. IRD is associated with deficient phytanic acid catabolism, as is Adult Refsum disease, but they are different disorders that should not be confused.
|
|
This protein family consists of TauD/TfdA taurine catabolism dioxygenases. The Escherichia coli tauD gene is required for the utilization of taurine (2-aminoethanesulfonic acid) as a sulfur source and is expressed only under conditions of sulfate starvation. TauD is an alpha-ketoglutarate-dependent dioxygenase catalyzing the oxygenolytic release of sulfite from taurine. The 2,4-dichlorophenoxyacetic acid/alpha-ketoglutarate dioxygenase from Burkholderia sp.
|
|
In the case of Baijiu production, typical amounts of 15–25% Jiuqu are used, sometimes as high as 50%, which consequently provides a major enzyme contribution to the mash to initiate catabolism. The exponential growth and reproduction of microbes after inoculation releases more enzymes in the process, inducing further catabolism of the substrate, to produce poly- and mono-saccharides, amino acids, peptides, CO2, alcohol and organic acids. Although only one type of starter is required, many Chinese breweries use two of more types of starters for added complexity in flavour. Modern Chinese brewing has also adopted many practices to optimize production and a 'seed mash' is now commonly prepared where the Jiuqu is added, often along with yeast (酵母 Jiao Mu or Chiao Mu or simply Jiao/Chiao 酵), to a small amount of the substrate.
|
|
Bertalanffy couldn't explain the meaning of the parameters \eta (the coefficient of anabolism) and k (coefficient of catabolism) in his works, and that caused a fair criticism from biologists. But the Bertalanffy equation is a special case of the Tetearing equation, that is a more general equation of the growth of a biological organism. The Tetearing equation determines the physical meaning of the coefficients \eta and k .
|
|
In situations when glycolysis is restricted by phosphate starvation, the switch to MGS serves to release phosphate from glycolytic metabolites for glyceraldehyde-3-phosphate dehydrogenase and to produce methylglyoxal, which is converted to pyruvate via lactate with the uncoupling of ATP synthesis. This interplay between the two enzymes allows the cell to shift triose catabolism between the formation of 1,3-bisphosphoglycerate and methylglyoxal based on available phosphates.
|
|
Floxuridine is a pyrimidine analog that acts as an inhibitor of the S-phase of cell division. This selectively kills rapidly dividing cells. Antimetabolites masquerade as pyrimidine-like molecules which prevents normal pyrimidines from being incorporated into DNA during the S phase of the cell cycle. Fluorouracil (the end-product of catabolism of floxuridine) blocks an enzyme which converts cytosine nucleosides into the deoxy derivative.
|
|
The oxidation of propionyl-CoA to form pyruvate is influenced by its necessity in Mycobacterium tuberculosis. Accumulation of propionyl-CoA can lead to toxic effects. In Mycobacterium tuberculosis, it has been suggested that the metabolism of propionyl-CoA is involved in cell wall biogenesis. A lack of such catabolism would therefore increase the susceptibility of the cell to various toxins, particularly to macrophage antimicrobial mechanisms.
|
|
Glutamine is the most abundant naturally occurring, nonessential amino acid in the human body, and one of the few amino acids that can directly cross the blood–brain barrier. Humans obtain glutamine through catabolism of proteins in foods they eat. In states where tissue is being built or repaired, like growth of babies, or healing from wounds or severe illness, glutamine becomes conditionally essential.
|
|
A basic organizing theme in biological systems is that increasing complexity in specialized tissues and organs, allows for greater specificity of function. This occurs for the processing of ethanol in the human body. The enzymes required for the oxidation reactions are confined to certain tissues. In particular, much higher concentration of such enzymes are found in the liver, which is the primary site for alcohol catabolism.
|
|
Ure2p is a yeast protein that represses transcription of genes involved in nitrogen catabolism. It specifically regulates the utilization of poor nitrogen sources in the presence of preferred nutrients such as ammonia or glutamine. Ure2p is one of the few yeast proteins that are known to be prions. At low frequency the protein adopts an alternative conformation that is auto- catalytic and self-propagating.
|
|
3,4-dihydroxyphenylalanine oxidative deaminase (, 3,4-dihydroxy-L- phenylalanine: oxidative deaminase, oxidative deaminase, DOPA oxidative deaminase, DOPAODA) is an enzyme with systematic name 3,4-dihydroxy-L- phenylalanine:oxygen oxidoreductase (deaminating). This enzyme catalyses the following chemical reaction : 2 L-dopa + O2 \rightleftharpoons 2 3,4-dihydroxyphenylpyruvate + 2 NH3 This enzyme is one of the three enzymes involved in L-dopa (3,4-dihydroxy-L-phenylalanine) catabolism in the bacterium Rubrivivax benzoatilyticus.
|
|
Phenylacetyl-CoA 1,2-epoxidase (, ring 1,2-phenylacetyl-CoA epoxidase, phenylacetyl-CoA monooxygenase, PaaAC, PaaABC(D)E) is an enzyme with systematic name phenylacetyl-CoA:oxygen oxidoreductase (1,2-epoxidizing). This enzyme catalyses the following chemical reaction : phenylacetyl-CoA + NADPH + H+ \+ O2 \rightleftharpoons 2-(1,2-epoxy-1,2-dihydrophenyl)acetyl-CoA + NADP+ \+ H2O Phenylacetyl-CoA 1,2-epoxidase participates in catabolism of phenylacetate in Escherichia coli and Pseudomonas putida.
|
|
D-arabitol-phosphate dehydrogenase (, APDH, D-arabitol 1-phosphate dehydrogenase, D-arabitol 5-phosphate dehydrogenase) is an enzyme with systematic name D-arabitol-phosphate:NAD+ oxidoreductase. This enzyme catalyses the following chemical reaction : D-arabitol 1-phosphate + NAD+ \rightleftharpoons D-xylulose 5-phosphate + NADH + H+ This enzyme participates in arabitol catabolism. The enzyme also converts D-arabitol 5-phosphate to D-ribulose 5-phosphate at a lower rate.
|
|
5,10-Methenyltetrahydrofolate (5,10-CH=THF) is a form of tetrahydrofolate that is an intermediate in metabolism. 5,10-CH=THF is a coenzyme that accepts and donates methenyl (CH=) groups. It is produced from 5,10-methylenetetrahydrofolate by either a NAD+ dependent methylenetetrahydrofolate dehydrogenase, or a NADP+ dependent dehydrogenase. It can also be produced as an intermediate in histidine catabolism, by formiminotransferase cyclodeaminase, from 5-formiminotetrahydrofolate.
|
|
Cathepsin B may enhance the activity of other proteases, including matrix metalloproteinase, urokinase (serine protease urokinase plasminogen activator), and cathepsin D, and thus it has an essential position for the proteolysis of extracellular matrix components, intercellular communication disruption, and reduced protease inhibitor expression. It is also involved in autophagy and catabolism, which is advantageous in tumor malignancy, and it is possibly involved in specific immune resistance.
|
|
The functional changes that occur with this disease are mostly metabolic. Accumulation of triglycerides in the body without an efficient mode for catabolism is thought to lead to the eventual symptoms of this disease. Upon digestion and absorption of fat by the small intestine, triglycerides are combined with vitamins and cholesterol to form chylomicrons. Chylomicrons travel from the intestine into the lymph system before entering the bloodstream.
|
|
Urea Conditions causing increased blood urea fall into three different categories: prerenal, renal, and postrenal. Prerenal azotemia can be caused by decreased blood flow through the kidneys (e.g. low blood pressure, congestive heart failure, shock, bleeding, dehydration) or by increased production of urea in the liver via a high protein diet or increased protein catabolism (e.g. stress, fever, major illness, corticosteroid therapy or gastrointestinal bleeding).
|
|
The Leloir pathway catalyzes the conversion of galactose to glucose. Galactose is found in dairy products, as well as in fruits and vegetables, and can be produced endogenously in the breakdown of glycoproteins and glycolipids. Three enzymes are required in the Leloir pathway: galactokinase, galactose-1-phosphate uridylyltransferase, and UDP-galactose 4-epimerase. Galactokinase catalyzes the first committed step of galactose catabolism, forming galactose 1-phosphate.
|
|
In molecular biology, the SR1 RNA is a small RNA (sRNA) produced by species of Bacillus and closely related bacteria. It is a dual-function RNA which acts both as a protein-coding RNA and as a regulatory sRNA. SR1 RNA is involved in the regulation of arginine catabolism. SR1 RNA binds to complementary stretches of ahrC mRNA (also known as argR and inhibits translation.
|
|
Glycogenolysis can supply the glucose needs of an adult body for 12–18 hours. When fasting continues for more than a few hours, falling insulin levels permit catabolism of muscle protein and triglycerides from adipose tissue. The products of these processes are amino acids (mainly alanine), free fatty acids, and lactic acid. Free fatty acids from triglycerides are converted to ketones, and to acetyl-CoA.
|
|
Uric acid competes with lactic acid and other organic acids for renal excretion in the urine. In GSD I increased availability of G6P for the pentose phosphate pathway, increased rates of catabolism, and diminished urinary excretion due to high levels of lactic acid all combine to produce uric acid levels several times normal. Although hyperuricemia is asymptomatic for years, kidney and joint damage gradually accrue.
|
|
Xanthine oxidase (XO, sometimes XAO) is a form of xanthine oxidoreductase, a type of enzyme that generates reactive oxygen species. These enzymes catalyze the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid. These enzymes play an important role in the catabolism of purines in some species, including humans. Xanthine oxidase is defined as an enzyme activity (EC 1.17.3.2).
|
|
Formiminoglutamic acid (FIGLU) is an intermediate in the catabolism of L-histidine to L-glutamic acid and marker for intracellular levels of folate. The FIGLU test is used to identify deficiencies of vitamin B12 or folate and is also found in liver disease. It is elevated with folate trapping, where it is accompanied by decreased methylmalonic acid, increased folate and a decrease in homocysteine.
|
|
This mutation on the PEX7 gene is also on chromosome 6q22-24, and was found in patients presenting with accumulation of phytanic acid with no PHYH mutation. Adult Refsum disease should not be confused with infantile Refsum disease, a peroxisome biogenesis disorder resulting from deficiencies in the catabolism of very long chain fatty acids and branched chain fatty acids (such as phytanic acid) and plasmalogen biosynthesis.
|
|
Differences between the catabolism of ether glycerophospholipids by specific phospholipases enzymes might be involved in the generation of lipid second messenger systems such as prostaglandins and arachidonic acid that are important in signal transduction. Ether lipids can also act directly in cell signaling, as the platelet- activating factor is an ether lipid signaling molecule that is involved in leukocyte function in the mammalian immune system.
|
|
Ascorbic acid, the main hydroxyl radical quencher, works as the cofactor providing the hydroxyl radical required to collagen cross-linking; lysine thus becomes hydroxylysine. GA1 worsens during stresses and catabolic episodes, such as fasts and infections. Endogenous catabolism of proteins could be an important route for glutaric acid production. It thus follows that collagen breakdown (and protein breakdown in general) should be prevented by all possible means.
|
|
Hambleton S, Sigler L (2005) Meliniomyces, a new anamorph genus for root-associated fungi with phylogenetic affinities to Rhizoscyphus ericae (≡ Hymenoscyphus ericae), Leotiomycetes. Studies in Mycology. 53:1-27.Midgley, D.J., Rosewarne, C.P., Greenfield, P., Li, D., Vockler, C.J., Hitchcock, C.J., Sawyer, N.A., Brett, R., Edwards, J., Pitt, J.I. & Tran-Dinh, N. (2016). Genomic insights into the carbohydrate catabolism of Cairneyella variabilis gen. nov.
|
|
Some key factors that determine overall rate include protein half-life, pH, and temperature. Protein half-life helps determine the overall rate as this designates the first step in protein catabolism. Depending on whether this step is short or long will influence the rest of the metabolic process. One key component in determining the protein half-life is based on the N-end rule.
|
|
Oxidative stress occurs when the production of reactive oxygen species (ROS) is greater than their catabolism. ROS production by the mitochondria is regulated by many diverse factors including SHC1. The SHC proteins are regulated by tyrosine phosphorylation and are part of the growth factor and stress-induced ERK activation. There have been findings that suggest a correlation between life span and the oxidative stress response.
|
|
5-Methyl-7-methoxyisoflavone, commonly referred to simply as methoxyisoflavone, is a chemical compound marketed as a bodybuilding supplement. However, there is no meaningful clinical evidence to support its usefulness. A study published in 2006 examined the effect of methoxyflavone on training adaptations and markers of muscle anabolism and catabolism. No measurable effects were observed in athletic performance or in levels of testosterone and cortisol.
|
|
The uxuA RNA motif is a conserved RNA structure that was discovered by bioinformatics. uxuA motif RNAs are found in the bacterial genus Vibrio. uxuA RNAs occur upstream of genes that encode mannonate dehydratase, which functions as part of the catabolism of glucuronate. This gene association could suggest that uxuA RNAs operate as cis-regulatory elements to control expression of the mannonate dehydratase genes.
|
|
Although CHID1 has no known function for certain, there are several proposed activities of the protein based on current knowledge. This protein may participate in metabolic processes such as chitin catabolism or carbohydrate metabolism. It may locate in various cellular compartments such as the cytoplasm, or in lysosomes all depending on certain post-translational modifications. Another study proposed that CHID1 may have roles in pathogen sensing.
|
|
The purine nucleotide cycle is a metabolic pathway in which ammonia and fumarate are generated from aspartate and inosine monophosphate (IMP) in order to regulate the levels of adenine nucleotides, as well as to facilitate the liberation of ammonia from amino acids. This pathway was first described by John Lowenstein, who outlined its importance in processes including amino acid catabolism and regulation of flux through glycolysis and the Krebs cycle.
|
|
Odd Chain Fatty Acid Oxidation to yield Propionyl-CoA, and subsequent metabolism by Propionyl-CoA Carboxylase The metabolic (catabolic fate) of propionyl-CoA depends on what environment it is being synthesized in. Therefore, propionyl- CoA in an anaerobic environment could have a different fate than that in an aerobic organism. The multiple pathways, either catabolism by propionyl-CoA carboxylase or methylcitrate synthase, also depend on the presence of various genes.
|
|
In molecular biology 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase (OHCU decarboxylase) is an enzyme involved in purine catabolism. It catalyses the decarboxylation of 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) into S(+)-allantoin. It is the third step of the conversion of uric acid (a purine derivative) to allantoin. Step one is catalysed by urate oxidase and step two is catalysed by hydroxyisourate hydrolase.
|
|
In biochemistry, the process of breaking down large molecules by splitting their internal bonds is catabolism. Enzymes which catalyse bond cleavage are known as lyases, unless they operate by hydrolysis or oxidoreduction, in which case they are known as hydrolases and oxidoreductases respectively. In proteomics, cleaving agents are used in proteome analysis where proteins are cleaved into smaller peptide fragments. Examples of cleaving agents used are cyanogen bromide, pepsin, and trypsin.
|
|
The catabolism of L-DOPA to synthesize 3-OMD This process is catalyzed by catechol O-methyltransferase methylates (COMT). The action of the enzyme makes it possible the reaction happens. This metabolite of L-DOPA formed, 3-OMD, is transaminated to vanilpyruvate by tyrosine aminotransferase. Vanilpyruvate is reduced to the final conversion: venillactate which are the same, predominantly by aromatic α-keto acid reductase and also by lactate dehydrogenase.
|
|
Xylose D-Xylose is a five-carbon aldose (pentose, monosaccharide) that can be catabolized or metabolized into useful products by a variety of organisms. There are at least four different pathways for the catabolism of D-xylose: An oxido-reductase pathway is present in eukaryotic microorganisms. Prokaryotes typically use an isomerase pathway, and two oxidative pathways, called Weimberg and Dahms pathways respectively, are also present in prokaryotic microorganisms.
|
|
A deficiency of LCAT causes accumulation of unesterified cholesterol in certain body tissues. Cholesterol effluxes from cells as free cholesterol and is transported in HDL as esterified cholesterol. LCAT is the enzyme that esterifies the free cholesterol on HDL to cholesterol ester and allows the maturation of HDL. LCAT deficiency does not allow for HDL maturation resulting in its rapid catabolism of circulating apolipoprotein A1 and apolipoprotein A2.
|
|
Ray started her career in the Department of Biochemistry, Indian Association of Cultivation of Science. Since December 2010, she is an Emeritus Scientist at Bose Institute, Kolkata. Ray's research has focused on understanding the biological role of methylglyoxal, a side-product of several metabolic pathways. Over the course of her career, she and her team have isolated, purified and characterized a series of enzymes involved in methylglyoxal anabolism and catabolism.
|
|
The first carboxypeptidases studied were those involved in the digestion of food (pancreatic carboxypeptidases A1, A2, and B). However, most of the known carboxypeptidases are not involved in catabolism; they help to mature proteins (e.g., Post-translational modification) or regulate biological processes. For example, the biosynthesis of neuroendocrine peptides such as insulin requires a carboxypeptidase. Carboxypeptidases also function in blood clotting, growth factor production, wound healing, reproduction, and many other processes.
|
|
Apolipoprotein B deficiency is an autosomal dominant disorder resulting from a missense mutation which reduces the affinity of apoB-100 for the low-density lipoprotein receptor (LDL Receptor). This causes impairments in LDL catabolism, resulting in decreased levels of low-density lipoprotein in the blood. The clinical manifestations are similar to diseases produced by mutations of the LDL receptor, such as familial hypercholesterolemia. Treatment may include, niacin or statin or ezetimibe.
|
|
Isobutyryl-CoA dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the ACAD8 gene on chromosome 11. The protein encoded by ACAD8 is a mitochondrial protein belongs to the acyl-CoA dehydrogenase family of enzymes, which function to catalyze the dehydrogenation of acyl-CoA derivatives in the metabolism of fatty acids or branched-chain amino acids. ACAD8 functions in catabolism of the branched-chain amino acid valine.
|
|
This variant is involved in the catabolism of trans-4-hydroxy-L-proline. From the given studies, in order to obtain D-amino acid dehydrogenase one must first introduce and express it within a given bacterial species, some of which have been previously referenced. It must then be purified under favorable conditions. These are based upon the particular species of D-amino acid dehydrogenase used in a given research experiment.
|
|
Vigabatrin is an irreversible mechanism-based inhibitor of gamma-aminobutyric acid aminotransferase (GABA-AT), the enzyme responsible for the catabolism of GABA. Inhibition of GABA-AT results in increased levels of GABA in the brain. Vigabatrin is a racemic compound, and its [S]-enantiomer is pharmacologically active., Crystal Structure (pdb:1OHW) showing vigabatrin binding to specific residues in the active site of GABA-AT, based on experiments by Storici et al.
|
|
Galactokinase is an enzyme (phosphotransferase) that facilitates the phosphorylation of α-D-galactose to galactose 1-phosphate at the expense of one molecule of ATP. Galactokinase catalyzes the second step of the Leloir pathway, a metabolic pathway found in most organisms for the catabolism of β-D-galactose to glucose 1-phosphate. First isolated from mammalian liver, galactokinase has been studied extensively in yeast, archaea, plants, and humans.
|
|
It is also involved in lysine catabolism that is known to occur in the mitochondrial matrix. Recent reports show that this protein is found both in the cytosol and the mitochondria, and the two forms likely arise from the use of alternative translation initiation sites. An additional variant encoding a different isoform has also been found for this gene. Mutations in this gene are associated with pyridoxine-dependent epilepsy.
|
|
Myophosphorylase is involved in the breakdown of glycogen to glucose for use in muscle. The enzyme removes 1,4 glycosyl residues from outer branches of glycogen and adds inorganic phosphate to form glucose-1-phosphate. Cells form glucose-1-phosphate instead of glucose during glycogen breakdown because the polar, phosphorylated glucose cannot leave the cell membrane and so is marked for intracellular catabolism. Myophosphorylase exists in the active form when phosphorylated.
|
|
The following diseases manifest by means of hematological dysfunction: granulocytosis, polycythemia, Trousseau sign, nonbacterial thrombotic endocarditis, and anemia. Hematological dysfunction of paraneoplastic syndromes can be seen from an increase of erythropoietin (EPO), which may occur in response to hypoxia or ectopic EPO production/altered catabolism. Erythrocytosis is common in regions of the liver, kidney, adrenal glands, lung, thymus, and central nervous system (as well as gynecological tumors and myosarcomas).
|
|
ABA can be catabolized to phaseic acid via CYP707A (a group of P450 enzymes) or inactivated by glucose conjugation (ABA-glucose ester) via the enzyme AOG. Catabolism via the CYP707As is very important for ABA homeostasis, and mutants in those genes generally accumulate higher levels of ABA than lines overexpressing ABA biosynthetic genes. In soil bacteria, an alternative catabolic pathway leading to dehydrovomifoliol via the enzyme vomifoliol dehydrogenase has been reported.
|
|
LAMP1 and LAMP2 make up about 50% of lysosomal membrane glycoproteins. (See LAMP1 for more information on both LAMP1 and LAMP2.) Both of these consist of polypeptides of about 40 kD, with the core polypeptide surrounded by 16 to 20 attached N-linked saccharides. The biological functions of these glycoproteins are disputed. They are believed to be significantly involved in operations of the lysosomes, including maintaining integrity, pH and catabolism.
|
|
Intermediates and enzymes in the Leloir pathway of galactose metabolism The Leloir pathway is a metabolic pathway for the catabolism of D-galactose. It is named after Luis Federico Leloir. In the first step, galactose mutarotase facilitates the conversion of β-D-galactose to α-D-galactose since this is the active form in the pathway. Next, α-D-galactose is phosphorylated by galactokinase to galactose 1-phosphate.
|
|
Carbon storage regulator A (CsrA) is an RNA binding protein. The CsrA homologs are found in most bacterial species, in the pseudomonads they are called repressor of secondary metabolites (RsmA and RsmE). The CsrA proteins generally bind to the Shine-Dalgarno sequence of messenger RNAs and either inhibit translation or facilitate mRNA decay. CsrA has a regulatory effect on glycogen biosynthesis and catabolism, glycolysis, biofilm formation and quorum sensing.
|
|
A number of 2,4-D-degrading bacteria have been isolated and characterized from a variety of environmental habitats.Cavalca, L., A. Hartmann, N. Rouard, and G. Soulas. 1999. Diversity of tfdC genes: distribution and polymorphism among 2,4-dichlorophenoxyacetic acid degrading soil bacteria. FEMS Microbiology Ecology 29: 45-58. Metabolic pathways for the compound’s degradation have been available for many years, and genes encoding 2,4-D catabolism have been identified for several organisms.
|
|
Heme oxygenase, an essential enzyme in heme catabolism, cleaves heme to form biliverdin, which is subsequently converted to bilirubin by biliverdin reductase, and carbon monoxide, a putative neurotransmitter. Heme oxygenase activity is induced by its substrate heme and by various nonheme substances. Heme oxygenase occurs as 2 isozymes, an inducible heme oxygenase-1 and a constitutive heme oxygenase-2. HMOX1 and HMOX2 (this enzyme) belong to the heme oxygenase family.
|
|
Proline dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the PRODH gene. The protein encoded by this gene is a mitochondrial proline dehydrogenase which catalyzes the first step in proline catabolism. Deletion of this gene has been associated with type I hyperprolinemia. The gene is located on chromosome 22q11.21, a region which has also been associated with the contiguous gene deletion syndromes: DiGeorge syndrome and CATCH22 syndrome.
|
|
Dr. Kopchick received his B.S. in biology in 1972 from the Indiana University of Pennsylvania (IUP). While attending IUP, he was a founding brother of a social fraternity Chi Alpha Sigma, which is now a chapter of Delta Tau Delta. In 1975, he received his M.S. in biology and chemistry from IUP. The title of his M.S. thesis was ‘Catabolism of alpha-amino adipate by Pseudomonas putida p2’.
|
|
Catabolism of proteinogenic amino acids. Amino acids are classified according to the abilities of their products to enter gluconeogenesis: In humans the main gluconeogenic precursors are lactate, glycerol (which is a part of the triacylglycerol molecule), alanine and glutamine. Altogether, they account for over 90% of the overall gluconeogenesis. Other glucogenic amino acids and all citric acid cycle intermediates (through conversion to oxaloacetate) can also function as substrates for gluconeogenesis.
|
|
Monoamine oxidase (MAO) is an extensively studied flavoenzyme due to its biological importance with the catabolism of norepinephrine, serotonin and dopamine. MAO oxidizes primary, secondary and tertiary amines, which nonenzymatically hydrolyze from the imine to aldehyde or ketone. Even though this class of enzyme has been extensively studied, its mechanism of action is still being debated. Two mechanisms have been proposed: a radical mechanism and a nucleophilic mechanism.
|
|
Niacin and nicotinamide are both converted into the coenzyme NAD. NAD converts to NADP by phosphorylation in the presence of the enzyme NAD+ kinase. NAD and NADP are coenzymes for many dehydrogenases, participating in many hydrogen transfer processes. NAD is important in catabolism of fat, carbohydrate, protein, and alcohol, as well as cell signaling and DNA repair, and NADP mostly in anabolism reactions such as fatty acid and cholesterol synthesis.
|
|
There are several pathways involved in lysine catabolism but the most commonly used is the saccharopine pathway, which primarily takes place in the liver (and equivalent organs) in animals, specifically within the mitochondria. This is the reverse of the previously described AAA pathway. In animals and plants, the first two steps of the saccharopine pathway are catalysed by the bifunctional enzyme, α-aminoadipic semialdehyde synthase (AASS), which possess both lysine-ketoglutarate reductase (LKR) (E.C 1.5.
|
|
4-Aminobutyrate aminotransferase (ABAT) is responsible for catabolism of gamma-aminobutyric acid (GABA), an important, mostly inhibitory neurotransmitter in the central nervous system, into succinic semialdehyde. The active enzyme is a homodimer of 50-kD subunits complexed to pyridoxal-5-phosphate. The protein sequence is over 95% similar to the pig protein. ABAT in liver and brain is controlled by 2 codominant alleles with a frequency in a Caucasian population of 0.56 and 0.44.
|
|
In biology, enzymes are protein-based catalysts in metabolism and catabolism. Most biocatalysts are enzymes, but other non-protein-based classes of biomolecules also exhibit catalytic properties including ribozymes, and synthetic deoxyribozymes.Nelson, D.L. and Cox, M.M. (2000) Lehninger, Principles of Biochemistry 3rd Ed. Worth Publishing: New York. . Biocatalysts can be thought of as intermediate between homogeneous and heterogeneous catalysts, although strictly speaking soluble enzymes are homogeneous catalysts and membrane-bound enzymes are heterogeneous.
|
|
Repressible Q binary expression system. The Q-system is based on two out of the seven genes of the qa gene cluster of the bread fungus Neurospora crassa. The genes of the qa cluster are responsible for the catabolism of quinic acid, which is used by the fungus as a carbon source in conditions of low glucose. The cluster contains a transcriptional activator qa-1F, a transcriptional repressor qa-1S, and five structural genes.
|
|
The total energy gained from the complete breakdown of one (six- carbon) molecule of glucose by glycolysis, the formation of 2 acetyl-CoA molecules, their catabolism in the citric acid cycle, and oxidative phosphorylation equals about 30 ATP molecules, in eukaryotes. The number of ATP molecules derived from the beta oxidation of a 6 carbon segment of a fatty acid chain, and the subsequent oxidation of the resulting 3 molecules of acetyl-CoA is 40.
|
|
L-arabinose operon is composed of structural genes and regulatory regions including the operator region (araO1, araO2) and the initiator region (araI1, araI2). The structural genes, araB, araA and araD, encode enzymes for L-arabinose catabolism. There is also a CAP binding site where CAP-cAMP complex binds to and facilitates catabolite repression, and results in positive regulation of araBAD when the cell is starved of glucose. Structure of L-arabinose operon of E. coli.
|
|
While the pathogenesis of LECT2 amyloidosis is unclear, the intact LECT2 protein may have a tendency to fold abnormally thereby forming non-soluble fibrils that are deposited in tissues. It has been suggested that individuals with the disease have an increase in LECT2 production and/or a decrease in LECT2 catabolism (i.e. breakdown) which leads to its tissue deposition. However, there appears to be clear genetic variations which lead LECT2 tissue deposition.
|
|
The Kynurenine pathway. Quinolinic acid is a byproduct of the kynurenine pathway, which is responsible for catabolism of tryptophan in mammals. This pathway is important for its production of the coenzyme nicotinamide adenine dinucleotide (NAD+) and produces several neuroactive intermediates including quinolinic acid, kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), and 3-hydroxyanthranilic acid (3-HANA). Quinolinic acid's neuroactive and excitatory properties are a result of NMDA receptor agonism in the brain.
|
|
It is not fully understood how the genetic differences between M. africanum and M. tuberculosis give rise to the lower pathogenicity of the former. However, it is known that the Region of Difference 9 (RD9) is lacking in M. africanum but present in M. tuberculosis. M. africanum also has notable differences in lipid catabolism and metabolism. Additionally, virulence pathways such as the dosR/Rv0081 regulon or ESAT-6 regulation are disrupted in M. africanum.
|
|
Indoleamine 2,3-dioxygenase is the first and rate- limiting enzyme of tryptophan catabolism through the kynurenine pathway. IDO is an important molecule in the mechanisms of tolerance and its physiological functions include the suppression of potentially dangerous inflammatory processes in the body. IDO also plays a role in natural defense against microorganisms. Expression of IDO is induced by interferon-gamma, which explains why the expression increases during inflammatory diseases or even during tumorigenesis.
|
|
Out of 141 blocks of consecutive MAEB stem-loops, 132 are positioned in a possible 5' UTR. Therefore, MAEB stem-loops are likely to correspond to a cis-regulatory element. It was observed that the genes apparently regulated by MAEB generally have a role in primary metabolism, i.e., the synthesis, catabolism or transport of small molecules; few MAEB- associated genes are involved in other functions, such as signal transduction, motility or replication.
|
|
Fumarylacetoacetate hydrolase (FAH) is a protein homodimer which cleaves fumarylacetoacetate at its carbon-carbon bond during a hydrolysis reaction. As a critical enzyme in phenylalanine and tyrosine metabolism, 4-Fumarylacetoacetate hydrolase catalyzes the final step in the catabolism of 4-fumarylacetoacetate and water into acetoacetate, fumarate, and H+ respectively. These hydrolytic reactions are essential during aromatic amino acid human metabolism. Furthermore, FAH does not share known protein sequence homologs with other nucleotides or amino acids.
|
|
Myo-inositol can be ingested from fruits and vegetables and actively transported into cells or instead directly synthesized from glucose. In the kidney, MIOX converts myo-inositol to glucuronic acid which is then able to enter the glucuronate-xylulose pathway for conversion to xylulose-5-phosphate. This product can then easily enter the pentose phosphate pathway. Hence, MIOX enables the conversion and catabolism of inositol to generate NADPH and other pentose sugars.
|
|
The use of the amino acid glutamine as an energy source is facilitated by the multistep catabolism of glutamine called glutaminolysis. This energy pathway is upregulated in cancer, which may represent a therapeutic target as cancer cells are thought to be more dependent on glutamine than healthy cells. This especially holds true for specific tumor types that are metabolically dysregulated, such as malignant brain tumors (i.e. glioblastoma) that carry mutations in the IDH1 gene.
|
|
It is created from the excess of ingested macronutrients, mainly carbohydrates. When glycogen is nearly depleted, the body begins lipolysis, the mobilization and catabolism of fat stores for energy. In this process fats, obtained from adipose tissue, or fat cells, are broken down into glycerol and fatty acids, which can be used to generate energy. The primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system.
|
|
The common ostrich is well adapted to hot, arid environments through specialization of excretory organs. The common ostrich has an extremely long and developed colon the length of approximately between the coprodeum and the paired caeca, which are around long. A well developed caeca is also found and in combination with the rectum forms the microbial fermentation chambers used for carbohydrate breakdown. The catabolism of carbohydrates produces around of water that can be used internally.
|
|
This drainage prevents loss of water by both lowering volume and increasing concentration of the urine. Angiotensin, on the other hand, causes vasoconstriction on the systemic arterioles, and acts as a dipsogen for ostriches. Both of these antidiuretic hormones work together to maintain water levels in the body that would normally be lost due to the osmotic stress of the arid environment. The end-product of catabolism of protein metabolism in animals is nitrogen.
|
|
Hence, a comfortable temperature in a heated building may be 18 - 22 degrees Celsius (64.4 - 71.6 degrees Fahrenheit). Humans produce an obligatory ~100 watts of heat energy as a by-product from basic processes like pumping blood, digesting, breathing, biochemical synthesis and catabolism etc. This is comparable to a common incandescent light-bulb. Hence, if the body were perfectly insulated, core temperature would continue to increase until lethal core temperatures were achieved.
|
|
CAP has a characteristic helix- turn-helix motif structure that allows it to bind to successive major grooves on DNA. The two helices are reinforcing, each causing a 43° turn in the structure, with an overall 94° degree turn in the DNA. This interaction opens up the DNA molecule, allowing RNA polymerase to bind and transcribe the genes involved in lactose catabolism. cAMP-CAP is required for transcription activation of the lac operon.
|
|
Protein metabolism denotes the various biochemical processes responsible for the synthesis of proteins and amino acids (anabolism), and the breakdown of proteins by catabolism. The steps of protein synthesis include transcription, translation, and post translational modifications. During transcription, RNA polymerase transcribes a coding region of the DNA in a cell producing a sequence of RNA, specifically messenger RNA (mRNA). This mRNA sequence contains codons: 3 nucleotide long segments that code for a specific amino acid.
|
|
Toll-like receptor 4 mediates cancer-induced muscle wasting in a Lewis lung carcinoma model. It does so by directly activating muscle catabolism and stimulating an innate immune response in the mice. Targeting of CD169+ macrophages in order to inhibit tumor Lewis lung carcinoma growth also caused depletion of bone and bone marrow in mice. This depletion disrupted bone homeostasis and caused bone weight loss and a bone density decrease in mice.
|
|
This reaction generates α-ketoglutarate (α-KG) and ammonia. Glutamate can then be regenerated from α-KG via the action of transaminases or aminotransferase, which catalyze the transfer of an amino group from an amino acid to an α-keto acid. In this manner, an amino acid can transfer its amine group to glutamate, after which GDH can then liberate ammonia via oxidative deamination. This is a common pathway during amino acid catabolism.
|
|
The free heme can then accelerate tissue damage by promoting peroxidative reactions and activation of inflammatory cascades. Hemopexin (Hx) is another plasma glycoprotein able to bind heme with high affinity. Hx sequesters heme in an inert, non-toxic form and transports it to the liver for catabolism and excretion. As long as both haptoglobin and hemopexin are saturated, the remaining free hemoglobins are filtered in the kidney and some of them will be reabsorbed by way of proximal tubules.
|
|
Decreases in skeletal muscle size and function have been reported since humans first began to explore space. Spaceflight results in the loss of lean body mass as determined by body composition measurements. Urinary amino acid and nitrogen excretion, both indirect measures of catabolism of lean body mass, are elevated during both brief and long spaceflights. Direct measurement of protein synthesis during spaceflight using 15N-glycine incorporation as a marker revealed an increase in whole-body protein synthesis rates.
|
|
S-methyl-5'-thioinosine phosphorylase (, MTIP, MTI phosphorylase, methylthioinosine phosphorylase) is an enzyme with systematic name S-methyl-5'-thioinosine:phosphate S-methyl-5-thio-alpha-D-ribosyl-transferase. This enzyme catalyses the following chemical reaction : S-methyl-5'-thioinosine + phosphate \rightleftharpoons hypoxanthine + S-methyl-5-thio-alpha-D-ribose 1-phosphate The catabolism of 5'-methylthioadenosine in Pseudomonas aeruginosa involves deamination to S-methyl-5'-thioinosine (EC 3.5.4.31, S-methyl-5'-thioadenosine deaminase) and phosphorolysis to hypoxanthine.
|
|
Vitamin B12 (cobalamins) contain a corrin ring similar in structure to porphyrin and is an essential coenzyme for the catabolism of fatty acids as well for the biosynthesis of methionine. DNA and RNA which store and transmit genetic information are composed of nucleic acid primary metabolites. First messengers are signaling molecules that control metabolism or cellular differentiation. These signaling molecules include hormones and growth factors in turn are composed of peptides, biogenic amines, steroid hormones, auxins, gibberellins etc.
|
|
The product of this gene is the polyamine oxidase. This enzyme potentially represents a new class of catabolic enzymes in the mammalian polyamine metabolic pathway capable of the efficient oxidation of polyamines. More than five transcript variants encoding four active isoenzymes have been identified for this gene, however, not all variants have been fully described. The characterized isoenzymes have distinctive biochemical characteristics and substrate specificities, suggesting the existence of additional levels of complexity in polyamine catabolism.
|
|
During branched-chain amino acid degradation, MCC performs a single step in the breakdown of leucine to eventually yield acetyl CoA and acetoacetate. MCC catalyzes the carboxylation of 3-methylcrotonyl CoA to 3-methylglutaconyl CoA, a critical step for leucine and isovaleric acid catabolism in species including mammals, plants and bacteria. 3-Methylglutaconyl CoA is then hydrated to produce 3-hydroxy-3-methylglutaryl CoA. 3-Hydroxy-3-methylglutaryl CoA is cleaved into two molecules, acetoacetate and acetyl CoA.
|
|
D-beta-hydroxybutyrate dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the BDH1 gene. This gene encodes a member of the short- chain dehydrogenase/reductase gene family. The encoded protein forms a homotetrameric lipid-requiring enzyme of the mitochondrial membrane and has a specific requirement for phosphatidylcholine for optimal enzymatic activity. The encoded protein catalyzes the interconversion of acetoacetate and (R)-3-hydroxybutyrate, the two major ketone bodies produced during fatty acid catabolism.
|
|
However supplementation with Vitamin A would be beneficial only in exceptional cases because normally the local catabolism of vitamin A will be the regulating factor. Squamous metaplasia of breast epithelia is known to be more prevalent in postmenopausal women (where it does not cause any problems at all). Staurosporine, a nonspecific protein kinase C inhibitor can induce squamous metaplasia in breast tissue while other known PKC inhibitors did not show this effect. cAMP stimulation can also induce squamous metaplasia.
|
|
The pathophysiology of septic shock is not entirely understood, but it is known that a key role in the development of severe sepsis is played by an immune and coagulation response to an infection. Both pro-inflammatory and anti-inflammatory responses play a role in septic shock. Septic shock involves a widespread inflammatory response that produces a hypermetabolic effect. This is manifested by increased cellular respiration, protein catabolism, and metabolic acidosis with a compensatory respiratory alkalosis.
|
|
Mitochondrial 2-oxodicarboxylate carrier also known as solute carrier family 25 member 21 (SLC25A21) is a protein that in humans is encoded by the SLC25A21 gene. It is a homolog of the S. cerevisiae ODC proteins, mitochondrial carriers that transport C5-C7 oxodicarboxylates across inner mitochondrial membranes. One of the species transported by ODC is 2-oxoadipate, a common intermediate in the catabolism of lysine, tryptophan, and hydroxylysine in mammals. Within mitochondria, 2-oxoadipate is converted into acetyl-CoA.
|
|
Nitisinone was discovered as part of a program to develop a class of herbicides called HPPD inhibitors. It is a member of the benzoylcyclohexane-1,3-dione family of herbicides, which are chemically derived from a natural phytotoxin, leptospermone, obtained from the Australian bottlebrush plant (Callistemon citrinus). HPPD is essential in plants and animals for catabolism, or breaking apart, of tyrosine. In plants, preventing this process leads to destruction of chlorophyll and the death of the plant.
|
|
Inhibiting inflammatory mediators could help prevent osteoarthritis progression. Cytokines and chemokines are both crucial in stimulating cartilage catabolism and blocking these inflammatory mediators. Studies have shown that treatment with NF-κB pathway inhibitor BAY11-7082 restores IL-1b-inhibited chondrogenesis of cartilage stem cells and in turn postpones progression of OA. Similarly, ample research shows that combined blockade of TNFa and IL-17 with bispecific antibodies reveals an inhibition of both cytokines for reduced cartilage degradation and proinflammatory responses.
|
|
The addition of Jiuqu to a cereal or pulse-based solution initiates the breakdown of carbohydrates, proteins and lipids into CO2, ethanol, organic acids and various other metabolites. This complex process of simultaneous catabolism and fermentation, often termed parallel or mash fermentation, is at variance with the beer and wine processes typical of the western world.Xiaoqing Mu et al Solid-State Fermented Alcoholic Beverages, in Chen, Jian, and Yang Zhu, eds. Solid State Fermentation for Foods and Beverages.
|
|
Carbohydrate catabolism is the breakdown of carbohydrates into smaller units. Carbohydrates are usually taken into cells once they have been digested into monosaccharides. Once inside, the major route of breakdown is glycolysis, where sugars such as glucose and fructose are converted into pyruvate and some ATP is generated. Pyruvate is an intermediate in several metabolic pathways, but the majority is converted to acetyl-CoA through aerobic (with oxygen) glycolysis and fed into the citric acid cycle.
|
|
Pathways are required for the maintenance of homeostasis within an organism and the flux of metabolites through a pathway is regulated depending on the needs of the cell and the availability of the substrate. The end product of a pathway may be used immediately, initiate another metabolic pathway or be stored for later use. The metabolism of a cell consists of an elaborate network of interconnected pathways that enable the synthesis and breakdown of molecules (anabolism and catabolism).
|
|
Monoamine oxidase B, also known as MAOB, is an enzyme that in humans is encoded by the MAOB gene. The protein encoded by this gene belongs to the flavin monoamine oxidase family. It is an enzyme located in the outer mitochondrial membrane. It catalyzes the oxidative deamination of biogenic and xenobiotic amines and plays an important role in the catabolism of neuroactive and vasoactive amines in the central nervous system and peripheral tissues (such as dopamine).
|
|
Factor D has a molecular weight of 23.5 kD and is present at a concentration of 1.8 mg/L of blood in healthy humans. The synthesis rate of Factor is approximately 1.33 mg/kg/day, and most of Factor D is eliminated through the kidney after catabolism in proximal tubules after re-absorption. The net effect is a high fractional metabolic rate of 60% per hour. In patients with normal kidney function, no Factor D was detectable in urine.
|
|
Anabolism is powered by catabolism, where large molecules are broken down into smaller parts and then used up in cellular respiration. Many anabolic processes are powered by the cleavage of adenosine triphosphate (ATP). Anabolism usually involves reduction and decreases entropy, making it unfavorable without energy input. The starting materials, called the precursor molecules, are joined together using the chemical energy made available from hydrolyzing ATP, reducing the cofactors NAD+, NADP+, and FAD, or performing other favorable side reactions.
|
|
APOE interacts significantly with the low-density lipoprotein receptor (LDLR), which is essential for the normal processing (catabolism) of triglyceride-rich lipoproteins. In peripheral tissues, APOE is primarily produced by the liver and macrophages, and mediates cholesterol metabolism. In the central nervous system, APOE is mainly produced by astrocytes and transports cholesterol to neurons via APOE receptors, which are members of the low density lipoprotein receptor gene family. APOE is the principal cholesterol carrier in the brain.
|
|
Saposins are a class of proteins involved in sphingolipid catabolism and antigen presentation of lipids in humans. Chris Ponting and Robert Russell identified a circularly permuted version of a saposin inserted into plant aspartic proteinase, which they nicknamed swaposin. Saposin and swaposin were the first known case of two natural genes related by a circular permutation. Hundreds of examples of protein pairs related by a circular permutation were subsequently discovered in nature or produced in the laboratory.
|
|
Upon treatment with aldehydes, bilanes may cyclize to give porphyrinogens and various open or closed oligomers and polymers. In living organisms, the biosynthesis of all natural porphyrins proceeds through the bilane preuroporphyrinogen, which is produced from four molecules of the monomer porphobilinogen, and then converted to the closed tetrapyrrole uroporphyrinogen III (or, in certain metabolic disorders, into uroporphyrinogen I). Also, the catabolism of hemoglobin in humans produces bilirubin, another linear tetrapyrrole that is a partially oxidized bilane.
|
|
Besides peripheral neuropathy (presenting as paresthesia or itching, burning or pain) and discoloration, swelling (edema) and desquamation may occur.Since mercury blocks the degradation pathway of catecholamines, epinephrine excess causes profuse sweating (diaphora), tachycardia, salivation and elevated blood pressure. Mercury is suggested to inactivate S-adenosyl-methionine, which is necessary for catecholamine catabolism by catechol-o-methyl transferase.Affected children may show red cheeks and nose, red (erythematous) lips, loss of hair, teeth, and nails, transient rashes, hypotonia and photophobia.
|
|
Cysteine dioxygenase (CDO) is a non-heme iron enzyme that catalyzes the conversion of L-cysteine to cysteine sulfinic acid (cysteine sulfinate). CDO plays an important role in cysteine catabolism, regulating intracellular levels of cysteine and responding changes in cysteine availability. As such, CDO is highly regulated and undergoes large changes in concentration and efficiency. It oxidizes cysteine to the corresponding sulfinic acid by activation of dioxygen, although the exact mechanism of the reaction is still unclear.
|
|
Propionyl-CoA is a coenzyme A derivative of propionic acid. It is composed of a 24 total carbon chain (without the coenzyme, it is a 3 carbon structure) and its production and metabolic fate depend on which organism it is present in. Several different pathways can lead to its production, such as through the catabolism of specific amino acids or the oxidation of odd-chain fatty acids. It later can be broken down by propionyl-CoA carboxylase or through the methylcitrate cycle.
|
|
Glycoside hydrolase family 38 CAZY GH_38 comprises enzymes with only one known activity; alpha-mannosidase () (). Lysosomal alpha- mannosidase is necessary for the catabolism of N-linked carbohydrates released during glycoprotein turnover. The enzyme catalyzes the hydrolysis of terminal, non-reducing alpha-D-mannose residues in alpha-D-mannosides, and can cleave all known types of alpha-mannosidic linkages. Defects in the gene cause lysosomal alpha-mannosidosis (AM), a lysosomal storage disease characterised by the accumulation of unbranched oligo-saccharide chains.
|
|
Lysine catabolism occurs through one of several pathways, the most common of which is the saccharopine pathway. Lysine plays several roles in humans, most importantly proteinogenesis, but also in the crosslinking of collagen polypeptides, uptake of essential mineral nutrients, and in the production of carnitine, which is key in fatty acid metabolism. Lysine is also often involved in histone modifications, and thus, impacts the epigenome. The ε-amino group often participates in hydrogen bonding and as a general base in catalysis.
|
|
The ε-ammonium group (NH3+) is attached to the fourth carbon from the α-carbon, which is attached to the carboxyl (C=OOH) group.Lysine. The Biology Project, Department of Biochemistry and Molecular Biophysics, University of Arizona. Due to its importance in several biological processes, a lack of lysine can lead to several disease states including defective connective tissues, impaired fatty acid metabolism, anaemia, and systemic protein-energy deficiency. In contrast, an overabundance of lysine, caused by ineffective catabolism, can cause severe neurological disorders.
|
|
The body uses glucose for energy. Without insulin, glucose is unable to enter the cells where it will be used for this and other anabolic ("building up") purposes, such as the synthesis of glycogen, proteins, and fatty acids. (PDF) Insulin is also an active preventor of the breakdown or catabolism of glycogen and fat. The absence of sufficient insulin causes this breaking-down process to be accelerated; it is the mechanism behind metabolizing fat instead of glucose and the appearance of ketones.
|
|
Here the addition of oxaloacetate to the mitochondrion does not have a net anaplerotic effect, as another citric acid cycle intermediate (malate) is immediately removed from the mitochondrion to be converted into cytosolic oxaloacetate, which is ultimately converted into glucose, in a process that is almost the reverse of glycolysis. In protein catabolism, proteins are broken down by proteases into their constituent amino acids. Their carbon skeletons (i.e. the de-aminated amino acids) may either enter the citric acid cycle as intermediates (e.g.
|
|
Catecholamines have a half-life of a few minutes when circulating in the blood. They can be degraded either by methylation by catechol-O- methyltransferases (COMT) or by deamination by monoamine oxidases (MAO). MAOIs bind to MAO, thereby preventing it from breaking down catecholamines and other monoamines. Catabolism of catecholamines is mediated by two main enzymes: catechol-O-methyltransferase (COMT) which is present in the synaptic cleft and cytosol of the cell and monoamine oxidase (MAO) which is located in the mitochondrial membrane.
|
|
PNPase, together with adenosine deaminase (ADA), serves a key role in purine catabolism, referred to as the salvage pathway. Mutations in ADA lead to an accumulation of (d)ATP, which inhibits ribonucleotide reductase, leading to a deficiency in (d)CTPs and (d)TTPs, which, in turn, induces apoptosis in T-lymphocytes and B-lymphocytes, leading to severe combined immunodeficiency (SCID). PNP- deficient patients will have an immunodeficiency problem. It affects only T-cells; B-cells are unaffected by the deficiency.
|
|
Carbon catabolite repression, or simply catabolite repression, is an important part of global control system of various bacteria and other micro-organisms. Catabolite repression allows micro-organisms to adapt quickly to a preferred (rapidly metabolisable) carbon and energy source first. This is usually achieved through inhibition of synthesis of enzymes involved in catabolism of carbon sources other than the preferred one. The catabolite repression was first shown to be initiated by glucose and therefore sometimes referred to as the glucose effect.
|
|
Protein catabolism (breakdown) has been estimated to supply 10% to 15% of the total energy requirement during a two-hour aerobic training session. This process could severely degrade the protein structures needed to maintain survival such as contractile properties of proteins in the heart, cellular mitochondria, myoglobin storage, and metabolic enzymes within muscles. The oxidative system (aerobic) is the primary source of ATP supplied to the body at rest and during low intensity activities and uses primarily carbohydrates and fats as substrates.
|
|
"In summary, enhanced catabolism of triglyceride-rich particles and reduced secretion of VLDL underlie the hypotriglyceridemic effect of fibrates, whereas their effect on HDL metabolism is associated with changes in HDL apolipoprotein expression." Fenofibrate is a fibric acid derivative, a prodrug comprising fenofibric acid linked to an isopropyl ester. It lowers lipid levels by activating peroxisome proliferator-activated receptor alpha (PPARα). PPARα activates lipoprotein lipase and reduces apoprotein CIII, which increases lipolysis and elimination of triglyceride-rich particles from plasma.
|
|
Again, the L-amino acid products can be used for biosynthesis or catabolized energy. Aminoacylase is involved in the regulation of the urea cycle. N-acetyl-L-glutamate is an allosteric activator of carbamoyl phosphate synthetase, a crucial enzyme that commits NH4+ molecules to the urea cycle. The urea cycle gets rid of excess ammonia (NH4+) in the body, a process that must be up-regulated during times of increased protein catabolism, as amino acid breakdown produces large amounts of NH4+.
|
|
Among common E. coli laboratory strains, the 4-HPA degradation pathway is not found in the commonly used K-12 strain, but it does appear in strains B, C, and W (the strain in which most research into the pathway has been done). Only strains containing this pathway are able to survive by metabolizing 4-HPA as the sole carbon source, showing that this pathway is required for catabolism of this compound, and likely for similar phenolic compounds as well.
|
|
Mouse liver PPARalpha transcriptome Human hepatocyte PPARalpha transcriptome PPAR-alpha is a transcription factor and a major regulator of lipid metabolism in the liver. PPAR-alpha is activated under conditions of energy deprivation and is necessary for the process of ketogenesis, a key adaptive response to prolonged fasting. Activation of PPAR-alpha promotes uptake, utilization, and catabolism of fatty acids by upregulation of genes involved in fatty acid transport, fatty acid binding and activation, and peroxisomal and mitochondrial fatty acid β-oxidation.
|
|
Cathepsin L1 is a protein that in humans is encoded by the CTSL1 gene. The protein encoded by this gene is a lysosomal cysteine protease that plays a major role in intracellular protein catabolism. Its substrates include collagen and elastin, as well as alpha-1 protease inhibitor, a major controlling element of neutrophil elastase activity. The encoded protein has been implicated in several pathologic processes, including myofibril necrosis in myopathies and in myocardial ischemia, and in the renal tubular response to proteinuria.
|
|
The Lysine riboswitch is a metabolite binding RNA element found within certain messenger RNAs that serve as a precision sensor for the amino acid lysine. Allosteric rearrangement of mRNA structure is mediated by ligand binding, and this results in modulation of gene expression. Lysine riboswitch are most abundant in Firmicutes and Gammaproteobacteria where they are found upstream of a number of genes involved in lysine biosynthesis, transport and catabolism. The lysine riboswitch has also been identified independently and called the L box.
|
|
The degradation of proteins occurs within the cells, as the amino acids have to pass through certain membranes before being able to be used for different processes. This first step to protein catabolism is breaking the protein down into amino acids by cleaving their peptide bonds, also known as proteolysis. The peptide bonds are broken up by the proteasome, which is able to hydrolyze the peptide bonds by using ATP energy. This process is further helped by the use of enzymes called proteases.
|
|
SA inhibits the enzyme 5-ALA dehydratase which converts aminolevulinic acid (5-ALA) into porphobilinogen, a precursor to porphyrin. Consequently, porphyrin deposits form in the bloodstream and cause neuropathic pain, leading to the acute neurological crises experienced by some patients. Additionally. SA can function to inhibit renal tubular function, the synthesis of heme, and the immune system. The accumulation of unprocessed tyrosine itself in the blood stream as a consequence of deficient catabolism can also lead to disruption of hormonal signaling and neurotransmission.
|
|
The cannabinoids (THC and CBD) are also discovered to bind human FABPs (1, 3, 5, and 7) that function as intracellular carriers, as THC and CBD inhibit the cellular uptake and catabolism of AEA by targeting FABPs. Competition for FABPs may in part or wholly explain the increased circulating levels of endocannabinoids reported after consumption of cannabinoids. Levels of fatty-acid-binding protein have been shown to decline with ageing in the mouse brain, possibly contributing to age-associated decline in synaptic activity.
|
|
Just before the seed germinates, ABA levels decrease; during germination and early growth of the seedling, ABA levels decrease even more. As plants begin to produce shoots with fully functional leaves, ABA levels begin to increase again, slowing down cellular growth in more "mature" areas of the plant. Stress from water or predation affects ABA production and catabolism rates, mediating another cascade of effects that trigger specific responses from targeted cells. Scientists are still piecing together the complex interactions and effects of this and other phytohormones.
|
|
Though present throughout the body, HO has significant activity in the spleen in the degradation of hemoglobin during erythrocyte recycling (0.8% of the erythrocyte pool per day), which accounts for ~80% of the heme derived endogenous CO production. The remaining 20% of heme derived CO production is largely attributed to hepatic catabolism of hemoproteins (myoglobin, cytochromes, catalase, peroxidases, soluble guanylate cyclase, nitric oxide synthase) and ineffective erythropoiesis in bone marrow. HO enzymes are degraded via ubiquitination. In humans three isoforms of heme oxygenase are known.
|
|
The increasing amount of bacterial genomic data provides new opportunities for understanding the genetic and molecular bases of the degradation of organic pollutants. Aromatic compounds are among the most persistent of these pollutants and lessons can be learned from the recent genomic studies of Burkholderia xenovorans LB400 and Rhodococcus sp. strain RHA1, two of the largest bacterial genomes completely sequenced to date. These studies have helped expand our understanding of bacterial catabolism, non-catabolic physiological adaptation to organic compounds, and the evolution of large bacterial genomes.
|
|
It employs one cofactor, thiamin diphosphate (TPP), and plays a key role in catabolism of oxalate, a highly toxic compound that is a product of the oxidation of carbohydrates in many bacteria and plants. Oxalyl-CoA decarboxylase is extremely important for the elimination of ingested oxalates found in human foodstuffs like coffee, tea, and chocolate, and the ingestion of such foods in the absence of Oxalobacter formigenes in the gut can result in kidney disease or even death as a result of oxalate poisoning.
|
|
A 2014 study noted that AMPK (AMP-activated protein kinase) and mTOR play important roles in managing different metabolic programs. It was also found that the protein complex v-ATPase-Ragulator was essential for activation of mTOR and AMPK. The v-ATPase-Ragulator complex is also used as an initiating sensor for energy stress, and serves as an endosomal docking site for LKB1-mediated AMPK activation by forming the v-ATPase-Ragulator-AXIN/LKB1-AMPK complex. This allows a switch between catabolism and anabolism.
|
|
Alcohol dehydrogenase 1A is an enzyme that in humans is encoded by the ADH1A gene. This gene encodes class I alcohol dehydrogenase, alpha subunit, which is a member of the alcohol dehydrogenase family. Members of this enzyme family metabolize a wide variety of substrates, including ethanol, retinol, other aliphatic alcohols, hydroxysteroids, and lipid peroxidation products. Class I alcohol dehydrogenase, consisting of several homo- and heterodimers of alpha, beta, and gamma subunits, exhibits high activity for ethanol oxidation and plays a major role in ethanol catabolism.
|
|
CYP26C1 (cytochrome P450, family 26, subfamily c, polypeptide 1) is a protein which in humans is encoded by the CYP26C1 gene. This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This enzyme is involved in the catabolism of all-trans- and 9-cis-retinoic acid, and thus contributes to the regulation of retinoic acid levels in cells and tissues.
|
|
Human ETF receives electrons from at least 14 flavoenzymes and transfers them to ETF-ubiquinone oxidoreductases (ETF:QO) in the inner mitochondrial membrane. ETF:QO in turn relays them to ubiquinone from where they enter the respiratory chain at complex III. Most of the flavoenzymes transferring electrons to ETF are participating in fatty acid oxidation, amino acid catabolism, and choline metabolism. ETF and ETF:QO thus represent an important hub for transfer of electrons from various redox reactions and feeding them into the respiratory chain for energy production.
|
|
ETF-QO subsequently relays the electrons via ubiquinone to complex III in the respiratory chain. The flavoenzymes that transfer electrons to ETF are involved in fatty acid beta oxidation, amino acid catabolism, choline metabolism, and special metabolic pathways. Defects in either of the ETF subunits or ETFDH cause multiple acyl CoA dehydrogenase deficiency (OMIM # 231680), earlier called glutaric acidemia type II. MADD is characterized by excretion of a series of substrates of the upstream flavoenzyes, e.g. glutaric, lactic, ethylmalonic, butyric, isobutyric, 2-methyl-butyric, and isovaleric acids.
|
|
Human ETF receives electrons from at least 14 flavoenzymes and transfers them to ETF-ubiquinone oxidoreductases (ETF:QO) in the inner mitochondrial membrane. ETF:QO in turn relays them to ubiquinone from where they enter the respiratory chain at complex III. Most of the flavoenzymes transferring electrons to ETF are participating in fatty acid oxidation, amino acid catabolism, and choline metabolism. ETF and ETF:QO thus represent an important hub for transfer of electrons from various redox reactions and feeding them into the respiratory chain for energy production.
|
|
ETF-QO subsequently relays the electrons via ubiquinone to complex III in the respiratory chain. The flavoenzymes that transfer electrons to ETF are involved in fatty acid beta oxidation, amino acid catabolism, choline metabolism, and special metabolic pathways. Defects in either of the ETF subunits or ETFDH cause multiple acyl CoA dehydrogenase deficiency (OMIM # 231680), earlier called glutaric acidemia type II. MADD is characterized by excretion of a series of substrates of the upstream flavoenzyes, e.g. glutaric, lactic, ethylmalonic, butyric, isobutyric, 2-methyl-butyric, and isovaleric acids.
|
|
Ketogenic baby formulas such as Nutricia KetoCal are available. With the ketogenic diet, ATP is synthesized by the catabolism of fatty acids rather than glucose, which produces the ketone bodies, 3-beta-hydroxybutyrate, acetoacetate, and acetone. Ketone bodies serve as an alternate source of energy for the body and the brain. Preliminary data from PDHD patients on the ketogenic diet indicate that in milder cases, there is a reduction in the frequency of seizures, abnormal EEG readings, ataxia and abnormal sleeping patterns, and extension of remission periods.
|
|
The CYP450 omega hydroxylases are accordingly better viewed as a subset of monooxygenases that have the ability to hydroxylate fatty acids. While once regarded as functioning mainly in the catabolism of dietary fatty acids, the omega oxygenases are now considered critical in the production or break-down of fatty acid-derived mediators which are made by cells and act within their cells of origin as autocrine signaling agents or on nearby cells as paracrine signaling agents to regulate various functions such as blood pressure control and inflammation.
|
|
Catabolism also improves increasing the athletes capacity to use fat and glycogen stores as an energy source. These metabolic processes are known as glycogenolysis, glycolysis and lipolysis. There is higher efficiency in oxygen transport and distribution. In recent years it has been recognized that oxidative enzymes such as succinate dehydrogenase (SDH) that enable mitochondria to break down nutrients to form ATP increase by 2.5 times in well trained endurance athletes In addition to SDH, myoglobin increases by 75-80% in well trained endurance athletes.
|
|
In mammalian cells, urea is the chief end-product of nitrogen catabolism and plays an important role in the urinary concentration mechanism. Thus, the plasma membrane of erythrocytes and some renal epithelial cells exhibit an elevated urea permeability that is mediated by highly selective urea transporters. In mammals, two urea transporters have been identified: the renal tubular urea transporter, UT2 (UT-A), and the erythrocyte urea transporter, UT11 (also called UT-B, coded for by the SLC14A1 gene). SLC14A2 and SLC14A1 constitute solute carrier family 14.
|
|
HO catalyzes the degradation of heme to biliverdin/bilirubin, ferrous ion, and CO. Though present throughout the body, HO has significant activity in the spleen in the degradation of hemoglobin during erythrocyte recycling (0.8% of the erythrocyte pool per day), which accounts for ~80% of heme derived endogenous CO production. The majority of the remaining 20% of heme derived CO production is attributed to hepatic catabolism of hemoproteins (myoglobin, cytochromes, catalase, peroxidases, soluble guanylate cyclase, nitric oxide synthase) and ineffective erythropoiesis in bone marrow.
|
|
SLC5A1 is medically relevant because of its role in the absorption of glucose and sodium, however, mutations in the gene can cause medical implications. A missense mutation in the SLC5A1 gene of exon 1 can cause problems creating the SGLT1 protein, leading to a rare glucose-galactose malabsorption disease. This is because the mutation destroys the transport function. Glucose-galactose malabsorption occurs when the lining of the intestinal cells cannot take in glucose and galactose which prevents the use of those molecules in catabolism and anabolism.
|
|
Evidence suggests that these anticonvulsants accelerate biotin catabolism, which means that it's necessary for people to take supplemental biotin, in addition to the usual minimum daily requirements, if they're treated with anticonvulsant medication(s) that have been linked to biotin deficiency. #Severe malnourishment # Prolonged oral antibiotic therapy: Prolonged use of oral antibiotics has been associated with biotin deficiency. Alterations in the intestinal flora caused by the prolonged administration of antibiotics are presumed to be the basis for biotin deficiency. # Genetic mutation: Mikati et al.
|
|
Prosaposin, also known as PSAP, is a protein which in humans is encoded by the PSAP gene. This highly conserved glycoprotein is a precursor for 4 cleavage products: saposins A, B, C, and D. Saposin is an acronym for Sphingolipid Activator PrO[S]teINs. Each domain of the precursor protein is approximately 80 amino acid residues long with nearly identical placement of cysteine residues and glycosylation sites. Saposins A-D localize primarily to the lysosomal compartment where they facilitate the catabolism of glycosphingolipids with short oligosaccharide groups.
|
|
The early MAOIs covalently bound to the monoamine oxidase enzymes, thus inhibiting them irreversibly; the bound enzyme could not function and thus enzyme activity was blocked until the cell made new enzymes. The enzymes turn over approximately every two weeks. A few newer MAOIs, a notable one being moclobemide, are reversible, meaning that they are able to detach from the enzyme to facilitate usual catabolism of the substrate. The level of inhibition in this way is governed by the concentrations of the substrate and the MAOI.
|
|
In contrast, the main function of NADPH is as a reducing agent in anabolism, with this coenzyme being involved in pathways such as fatty acid synthesis and photosynthesis. Since NADPH is needed to drive redox reactions as a strong reducing agent, the NADP/NADPH ratio is kept very low. Although it is important in catabolism, NADH is also used in anabolic reactions, such as gluconeogenesis. This need for NADH in anabolism poses a problem for prokaryotes growing on nutrients that release only a small amount of energy.
|
|
Anabolism is the set of constructive metabolic processes where the energy released by catabolism is used to synthesize complex molecules. In general, the complex molecules that make up cellular structures are constructed step-by-step from small and simple precursors. Anabolism involves three basic stages. First, the production of precursors such as amino acids, monosaccharides, isoprenoids and nucleotides, secondly, their activation into reactive forms using energy from ATP, and thirdly, the assembly of these precursors into complex molecules such as proteins, polysaccharides, lipids and nucleic acids.
|
|
Deiodinases also provide spatial and temporal developmental control of thyroid hormone levels. D3 levels are highest early in development and decrease over time, while D2 levels are high at moments of significant metamorphic change in tissues. Thus D2 enables production of sufficient T3 at necessary time points while D3 may shield tissue from overexposure to T3. Also, iodothyronine deiodinases (type 2 y 3; DIO2 and DIO3, respectively) respond to seasonal changes in photoperiod-driven melatonin secretion and govern peri-hypothalamic catabolism of the prohormone thyroxine (T4).
|
|
4-Hydroxyphenylpyruvate dioxygenase (HPPD), also known as α-ketoisocaproate dioxygenase (KIC dioxygenase), is an Fe(II)-containing non-heme oxygenase that catalyzes the second reaction in the catabolism of tyrosine - the conversion of 4-hydroxyphenylpyruvate into homogentisate. HPPD also catalyzes the conversion of phenylpyruvate to 2-hydroxyphenylacetate and the conversion of α-ketoisocaproate to β-hydroxy β-methylbutyrate. HPPD is an enzyme that is found in nearly all aerobic forms of life. This reaction shows the conversion of 4-hydroxyphenylpyruvate into homogentisate by HPPD.
|
|
IDO2 (indolamine-2,3-dioxygenase) is an enzyme with protein size of 420 amino acids (47 kDa) that is used for catabolism of tryptophan. In organisms, other enzymes participate in L-tryptophan cleavage, namely IDO1 and TDO. Despite of IDO1 and IDO2 are closely related enzymes originating by gene duplication and sharing high level (43%) of sequence homology, they differentiate by their kinetics, function and expression pattern. Genes encoding IDO1 and IDO2 have similar genomic structure and are situated closely to each other on chromosome 8.
|
|
A problem with SIA occurs if birds undergo protein catabolism during migration and their isotopic information is subsequently lost as a result of blood-cell replacement. SIA is difficult to employ on birds that switch their diets seasonally due to the difficulty of separating isotopic changes due to location change from isotopic changes due to diet change. The elements that are primarily analyzed for SIA are: carbon, nitrogen, oxygen, hydrogen, and sulphur. Isotopic variation among plants is largely based on differences in photosynthetic pathways.
|
|
The structure of a protease (TEV protease) complexed with its peptide substrate in black with catalytic residues in red.() A protease (also called a peptidase or proteinase) is an enzyme that catalyzes (increases the rate of) proteolysis, the breakdown of proteins into smaller polypeptides or single amino acids. They do this by cleaving the peptide bonds within proteins by hydrolysis, a reaction where water breaks bonds. Proteases are involved in many biological functions, including digestion of ingested proteins, protein catabolism (breakdown of old proteins), and cell signalling.
|
|
Overexpression of Apo-CIII in humans contributes to atherosclerosis. Two novel susceptibility haplotypes (specifically, P2-S2-X1 and P1-S2-X1) have been discovered in ApoAI-CIII-AIV gene cluster on chromosome 11q23; these confer approximately threefold higher risk of coronary heart disease in normal as well as non- insulin diabetes mellitus. In persons with type 2 diabetes, elevated plasma Apo-CIII is associated with higher plasma triglycerides and greater coronary artery calcification (a measure of subclinical atherosclerosis). Apo-CIII delays the catabolism of triglyceride rich particles.
|
|
During the acute phase, the liver redirects protein synthesis, causing up-regulation of certain proteins and down-regulation of others. Measuring the serum level of proteins that are up- and down-regulated during the acute phase can reveal extremely important information about the patient's nutritional state. The most important up-regulated protein is C-reactive protein, which can rapidly increase 20- to 1,000-fold during the acute phase. Hypermetabolism also causes expedited catabolism of carbohydrates, proteins, and triglycerides in order to meet the increased metabolic demands.
|
|
Tumor lysis syndrome, an emergency condition that may result from blood cancers, produces high uric acid levels in blood when tumor cells release their contents into the blood, either spontaneously or following chemotherapy. Tumor lysis syndrome may lead to acute kidney injury when uric acid crystals are deposited in the kidneys. Treatment includes hyperhydration to dilute and excrete uric acid via urine, rasburicase to reduce levels of poorly soluble uric acid in blood, or allopurinol to inhibit purine catabolism from adding to uric acid levels.
|
|
Deficiencies in any of the enzymes in the catabolism of phenylalanine and tyrosine, like GSTZ1, has led to diseases such as alkaptonuria, phenylketonuria, and several forms of tyrosinemia. A lack of GSTZ1, specifically, leads to the amalgamation of maleylacetoacetate and succinylacetone which has been observed to cause oxidative stress. Also, scarcities have been seen to alter the metabolism of certain drugs and xenobiotics in mice. Most importantly, researchers have successfully genetically engineered GSTZ1 to mimic one of the most significant antioxidant enzymes, glutathione peroxidase (GPX).
|
|
Newly synthesized proteins (black) are often further modified, such as by binding to an effector molecule (orange), to become fully active. Between successive cell divisions, cells grow through the functioning of cellular metabolism. Cell metabolism is the process by which individual cells process nutrient molecules. Metabolism has two distinct divisions: catabolism, in which the cell breaks down complex molecules to produce energy and reducing power, and anabolism, in which the cell uses energy and reducing power to construct complex molecules and perform other biological functions.
|
|
Methylglyoxal synthase provides an alternative catabolic pathway for triose phosphates created in glycolysis. It has activity levels similar to that of glyceraldehyde-3-phosphate dehydrogenase from glycolysis, suggesting an interplay between the two enzymes in the breakdown of triose phosphates. Indeed, MGS is strongly inhibited by phosphate concentrations that are close to the Km of phosphate serving as substrate for glyceraldehyde-3-phosphate dehydrogenase and is, therefore, inactive at normal intracellular conditions. Triose phosphate catabolism switches over to MGS when phosphate concentrations are too low for glyceraldehyde-3-phosphate dehydrogenase activity.
|
|
Secondly, glyoxalase ІІ hydrolyses these thiolesters and in the case of methylglyoxal catabolism, produces D-lactate and GSH from S-D-lactoyl-glutathione. This system shows many of the typical features of the enzymes that dispose of endogenous toxins. Firstly, in contrast to the amazing substrate range of many of the enzymes involved in xenobiotic metabolism, it shows a narrow substrate specificity. Secondly, intracellular thiols are required as part of its enzymatic mechanism and thirdly, the system acts to recycle reactive metabolites back to a form which may be useful to cellular metabolism.
|
|
LECT2 as a hepatokine, a substance made and released into the circulation by liver hepatocyte cells that acts as a hormone or signaling agent to regulate the function of other cells. While the pathogenesis of LECT2 amyloidosis is unclear, the intact LECT2 protein may have a tendency to fold abnormally thereby forming non-soluble fibrils that are deposited in tissues. It has been suggested that individuals with the disease have an increase in LECT2 production and/or a decrease in LECT2 catabolism (i.e. breakdown) which may increase its tendency to deposit in tissues.
|
|
The formation of cysts is induced by chemical factors and is accompanied by metabolic shifts, changes in catabolism, respiration, and biosynthesis of macromolecules; it is also affected by aldehyde dehydrogenase and the response regulator AlgR. The cysts of Azotobacter are spherical and consist of the so- called "central body" – a reduced copy of vegetative cells with several vacuoles – and the "two-layer shell". The inner part of the shell is called intine and has a fibrous structure. The outer part has a hexagonal crystalline structure and is called exine.
|
|
Many synthetic steroidic compounds like some sexual hormones frequently appear in municipal and industrial wastewaters, acting as environmental pollutants with strong metabolic activities negatively affecting the ecosystems. Since these compounds are common carbon sources for many different microorganisms their aerobic and anaerobic mineralization has been extensively studied. The interest of these studies lies on the biotechnological applications of sterol transforming enzymes for the industrial synthesis of sexual hormones and corticoids. Very recently, the catabolism of cholesterol has acquired a high relevance because it is involved in the infectivity of the pathogen Mycobacterium tuberculosis (Mtb).
|
|
BUN is an indication of renal (kidney) health. The normal range is 2.1–7.1 mmol/L or 6–20 mg/dL. The main causes of an increase in BUN are: high protein diet, decrease in glomerular filtration rate (GFR) (suggestive of kidney failure), decrease in blood volume (hypovolemia), congestive heart failure, gastrointestinal hemorrhage, fever, rapid cell destruction from infections, athletic activity, excessive muscle breakdown, and increased catabolism. Hypothyroidism can cause both decreased GFR and hypovolemia, but BUN-to-creatinine ratio has been found to be lowered in hypothyroidism and raised in hyperthyroidism.
|
|
3-Aminoisobutyric acid (or β-aminoisobutyric acid, BAIBA) is a product formed by the catabolism of thymine. During exercise, the increase of PGC-1α protein triggers the secretion of BAIBA from exercising muscles to blood (concentration 2 to 3 μM in human serum). When BAIBA reaches the white fat tissue, it activates the expression of thermogenic genes via PPARα receptors, resulting in a browning of white fat cells. One of the consequences of the BAIBA activity is the increase of the background metabolism of the BAIBA target cells.
|
|
Brambell was appointed Lloyd Roberts Professor and Head of the Department of Zoology at Bangor University in 1930 at age 29 years. From that time until his retirement 38 years later, he brought great distinction to his Department and College. He was the father of the field of transmission of immunity. As part of his quantitative and temporal studies on transmission, he defined the first Fc receptor system for IgG, and furthermore recognized the link between transmission of passive immunity from mother to young and protection from catabolism via IgG.
|
|
Ferrochelatase interacts with numerous other enzymes involved in heme biosynthesis, catabolism, and transport, including protoporphyrinogen oxidase, 5-aminolevulinate synthase, ABCB10, ABCB7, succinyl-CoA synthetase, and mitoferrin-1. Multiple studies have suggested the existence of an oligomeric complex that enables substrate channeling and coordination of overall iron and porphyrin metabolism throughout the cell. N-methylmesoporphyrin (N-MeMP) is a competitive inhibitor with protoporphyrin IX and is thought to be a transition state analog. As such, N-MeMP has been used extensively as a stabilizing ligand for x-ray crystallography structure determination.
|
|
High levels of uric acid often present as a consequence of elevated lactic acid in GSD I patients. When lactate levels are elevated, blood-borne lactic acid competes for the same kidney tubular transport mechanism as urate, limiting the rate that urate can be cleared by the kidneys into the urine. If present, increased purine catabolism is an additional contributing factor. Uric acid levels of 6 to 12 mg/dl (530 to 1060 umol/L) are common among GSD I patients, if the disease is not properly treated.
|
|
Objectionable odors are likely when the rate of oxygen transfer from the lagoon surface is less than the rate of oxygen consumption in the lower levels of the lagoon. A facultative lagoon might provide 50 pounds of oxygen per day (5 grams of oxygen per square meter per day) for biochemical catabolism. Biological activity within a facultative lagoon varies directly with temperature. Warm weather will require large oxygen transfer rates, and waste accumulation during cold weather can cause short-term warm weather oxygen requirements to exceed long-term waste loading rates.
|
|
Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost or eliminated by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high."Bioaccumulation of Marine Pollutants [and Discussion]", by G. W. Bryan, M. Waldichuk, R. J. Pentreath and Ann Darracott.
|
|
Glomerulus and Bowman's capsule. The blood filtered through the glomerular filtration barrier corresponds to the primary urine collected in the Bowman's capsule. It has been speculated that SPS is both caused by, and exacerbates, cardiovascular disease. It was stated in 2014 that the kidneys have a role in maintaining the equilibrium between production and catabolism of most proteins between about 5 and 30 kDa in molecular mass and that failure to do so results in serious disease and strongly increased mortality, when the kidney disorder shrunken pore syndrome was identified.
|
|
Digestion is the breakdown of large insoluble food molecules into small water- soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes.
|
|
Lens fibers also have a very extensive cytoskeleton that maintains the precise shape and packing of the lens fibers; disruptions/mutations in certain cytoskeletal elements can lead to the loss of transparency. The lens blocks most ultraviolet light in the wavelength range of 300–400 nm; shorter wavelengths are blocked by the cornea. The pigment responsible for blocking the light is 3-hydroxykynurenine glucoside, a product of tryptophan catabolism in the lens epithelium. High intensity ultraviolet light can harm the retina, and artificial intraocular lenses are therefore manufactured to also block ultraviolet light.
|
|
This gene encodes class I alcohol dehydrogenase, gamma subunit, which is a member of the alcohol dehydrogenase family. Members of this enzyme family metabolize a wide variety of substrates, including ethanol (beverage alcohol), retinol, other aliphatic alcohols, hydroxysteroids, and lipid peroxidation products. Class I alcohol dehydrogenase, consisting of several homo- and heterodimers of alpha, beta, and gamma subunits, exhibit high activity for ethanol oxidation and play a major role in ethanol catabolism. Three genes encoding alpha, beta and gamma subunits are tandemly organized in a genomic segment as a gene cluster.
|
|
Alcohol dehydrogenase 1B is an enzyme that in humans is encoded by the ADH1B gene. The protein encoded by this gene is a member of the alcohol dehydrogenase family. Members of this enzyme family metabolize a wide variety of substrates, including ethanol (beverage alcohol), retinol, other aliphatic alcohols, hydroxysteroids, and lipid peroxidation products. The encoded protein, known as ADH1B or beta-ADH, can form homodimers and heterodimers with ADH1A and ADH1C subunits, exhibits high activity for ethanol oxidation and plays a major role in ethanol catabolism (oxidizing ethanol into acetaldehyde).
|
|
The CsrB RNA is a non-coding RNA that binds to approximately 9 to 10 dimers of the CsrA protein. The CsrB RNAs contain a conserved motif CAGGXXG that is found in up to 18 copies and has been suggested to bind CsrA. The Csr regulatory system has a strong negative regulatory effect on glycogen biosynthesis, glyconeogenesis and glycogen catabolism and a positive regulatory effect on glycolysis. In other bacteria such as Erwinia carotovora the RsmA protein has been shown to regulate the production of virulence determinants, such extracellular enzymes.
|
|
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involved in a wide range of physiological processes, including stress response, immune response, and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior. Some common naturally occurring steroid hormones are cortisol (), corticosterone (), cortisone () and aldosterone (). (Note that cortisone and aldosterone are isomers.) The main corticosteroids produced by the adrenal cortex are cortisol and aldosterone.
|
|
MSUD management also involves a specially tailored metabolic formula, a modified diet, and lifestyle precautions such as avoiding fatigue and infections, as well as consuming regular, sufficient calories in proportion to physical stress and exertion. Without sufficient calories, catabolism of muscle protein will result in metabolic crisis. Those with MSUD must be hospitalised for intravenous infusion of sugars and nasogastric drip-feeding of formula, in the event of metabolic decompensation, or lack of appetite, diarrhea or vomiting. Food avoidance, rejection of formula and picky eating are all common problems with MSUD.
|
|
4-maleylacetoacetate is converted to 4-fumarylacetoacetate, this compound can be broken down into fumarate and acetoacetate by the enzyme fumarylacetoacetate hydrolase. The conversion of 4-maleylacetoacetate to fumarylacetoacetate is a step in the catabolism of phenylalanine and tyrosine, amino acids acquired through dietary protein consumption. When 4-maleylacetoacetate isomerase is unable to function properly, the 4-maleylacetoacetate may be converted instead to succinylacetoacetate and further broken down into succinate and acetoacetate by fumarylacetoacetate hydrolase. This image shows the pathway that 4-maleylacetoacetate follows when 4-maleylacetoacetate isomerase is not present.
|
|
Microbial desalination cells stem from microbial fuel cells, deviating by no longer requiring the use of a mediator and instead relying on the charged components of the internal sludge to power the desalination process. Microbial desalination cells therefore do not require additional bacteria to mediate the catabolism of the substrate during biofilm oxidation on the anodic side of the capacitor. MDCs and other bio- electrical systems are favored over reverse osmosis, nanofiltration and other desalination systems due to lower costs, energy and environmental impacts associated with bio-electrical systems.
|
|
Methylglyoxal. The principal physiological function of glyoxalase I is the detoxification of methylglyoxal, a reactive 2-oxoaldehyde that is cytostatic at low concentrations and cytotoxic at millimolar concentrations. Methylglyoxal is a by-product of normal biochemistry that is a carcinogen, a mutagen and can chemically damage several components of the cell, such as proteins and nucleic acids. Methylglyoxal is formed spontaneously from dihydroxyacetone phosphate, enzymatically by triosephosphate isomerase and methylglyoxal synthase, as also in the catabolism of threonine. To minimize the amount of toxic methylglyoxal and other reactive 2-oxoaldehydes, the glyoxalase system has evolved.
|
|
DNA analysis identified genes of the N-acetylneuraminate scavenging and catabolism pathway. Biochemical tests including metabolism of glucose, mannose, lactose, sucrose, arginine, aesculin, urea and phosphatase activity performed on M. alligatoris isolates showed that the organism ferments glucose, mannose, lactose, and sucrose and displays phosphatase activity. DNA sequencing analysis revealed genes encoding a complement of glycosidases, which include hyaluronidases, two sialidases, three β-galactosidases, α-amylase (glycogenase), and two glycosyltransferases. M. alligatoris differs from other species of the Mycoplasma genus by the aforementioned complement of sialidases, which are enzymes of the hydrolase class.
|
|
The second major step in the catabolism of the branched-chain amino acids, isoleucine, leucine, and valine, is catalyzed by the branched- chain alpha-keto acid dehydrogenase complex (BCKD; EC 1.2.4.4), an inner- mitochondrial enzyme complex that consists of 3 catalytic components: a heterotetrameric (alpha2, beta2) branched-chain alpha-keto acid decarboxylase (E1), a homo-24-meric dihydrolipoyl transacylase (E2; MIM 248610), and a homodimeric dihydrolipoamide dehydrogenase (E3; MIM 238331). The reaction is irreversible and constitutes the first committed step in BCAA oxidation. The complex also contains 2 regulatory enzymes, a kinase and a phosphorylase.
|
|
Branched-chain keto acid dehydrogenase is a multienzyme complex associated with the inner membrane of mitochondria, and functions in the catabolism of branched-chain amino acids. The complex consists of multiple copies of 3 components: branched-chain alpha-keto acid decarboxylase (E1), lipoamide acyltransferase (E2), and lipoamide dehydrogenase (E3). This gene encodes the E1 beta subunit, and mutations therein have been associated with maple syrup urine disease (MSUD), type 1B. Alternative splicing at this locus results in transcript variants with different 3' noncoding regions, but encoding the same isoform.
|
|
During the late stages of parasite replication red cells are adherent to venous endothelium, and inhibiting this attachment could suppress replication. Sickle hemoglobin induces the expression of heme oxygenase-1 in hematopoietic cells. Carbon monoxide, a byproduct of heme catabolism by heme oxygenase-1(HO-1), prevents an accumulation of circulating free heme after Plasmodium infection, suppressing the pathogenesis of experimental cerebral malaria. Other mechanisms, such as enhanced tolerance to disease mediated by HO-1 and reduced parasitic growth due to translocation of host micro-RNA into the parasite, have been described.
|
|
The mechanism of action for HPPD inhibitors was misunderstood for the first twenty years that these products were sold, starting in 1980. They were originally thought to be inhibitors of protoporphyrinogen oxidase (protox). 4-Hydroxyphenylpyruvate dioxygenase (HPPD) is an enzyme found in both plants and animals which catalyzes the catabolism of the amino acid tyrosine. Preventing the breakdown of tyrosine has three negative consequences: the excess of tyrosine stunts growth; the plant suffers oxidative damage due to lack of tocopherols (vitamin E); and chlorophyll is destroyed due to lack of carotenoids that protect it.
|
|
Consequently, animal testing and clinical trials are major elements of in vivo research. In vivo testing is often employed over in vitro because it is better suited for observing the overall effects of an experiment on a living subject. In drug discovery, for example, verification of efficacy in vivo is crucial, because in vitro assays can sometimes yield misleading results with drug candidate molecules that are irrelevant in vivo (e.g., because such molecules cannot reach their site of in vivo action, for example as a result of rapid catabolism in the liver).
|
|
Metabolic acidosis may result from either increased production of metabolic acids, such as lactic acid, or disturbances in the ability to excrete acid via the kidneys, such as either renal tubular acidosis or the acidosis of kidney failure, which is associated with an accumulation of urea and creatinine as well as metabolic acid residues of protein catabolism. An increase in the production of other acids may also produce metabolic acidosis. For example, lactic acidosis may occur from: #severe (PaO2 <36mm Hg) hypoxemia causing a fall in the rate of oxygen diffusion from arterial blood to tissues. #hypoperfusion (e.g.
|
|
Propionyl-CoA production through the catabolism of fatty acids is also associated with thioesterifcation. In a study concerning Aspergillus nidulans, it was found that with the inhibition of a methylcitrate synthase gene, mcsA, of the pathway described above, production of distinct polyketides was inhibited as well. Therefore, the utilization of propionyl-CoA through the methylcitrate cycle decreases its concentration, while subsequently increasing the concentration of polyketides. A polyketide differs from the more commonly known compound, the polypeptide, in that a polyketide is a structure commonly found in fungi that is made of acetyl- and malonyl- CoAs.
|
|
Abscisic acid accumulates within seeds during fruit maturation, preventing seed germination within the fruit or before winter. Abscisic acid's effects are degraded within plant tissues during cold temperatures or by its removal by water washing in and out of the tissues, releasing the seeds and buds from dormancy. ABA exists in all parts of the plant, and its concentration within any tissue seems to mediate its effects and function as a hormone; its degradation, or more properly catabolism, within the plant affects metabolic reactions and cellular growth and production of other hormones. Plants start life as a seed with high ABA levels.
|
|
Lysine has also been shown to play a role in anaemia, as lysine is suspected to have an effect on the uptake of iron and, subsequently, the concentration of ferritin in blood plasma. However, the exact mechanism of action is yet to be elucidated. Most commonly, lysine deficiency is seen in non-western societies and manifests as protein-energy malnutrition, which has profound and systemic effects on the health of the individual. There is also a hereditary genetic disease that involves mutations in the enzymes responsible for lysine catabolism, namely the bifunctional AASS enzyme of the saccharopine pathway.
|
|
It is therefore unlikely that the reduction in body cholesterol is due to adsorption to this fermented fiber in the colon. # There might be alterations in the end- products of bile acid bacterial metabolism or the release of short chain fatty acids which are absorbed from the colon, return to the liver in the portal vein and modulate either the synthesis of cholesterol or its catabolism to bile acids. # The prime mechanism whereby fiber influences cholesterol metabolism is through bacteria binding bile acids in the colon after the initial deconjugation and dehydroxylation. The sequestered bile acids are then excreted in feces.
|
|
If catabolism of alcohol goes all the way to completion, then, we have a very exothermic event yielding some of energy. If the reaction stops part way through the metabolic pathways, which happens because acetic acid is excreted in the urine after drinking, then not nearly as much energy can be derived from alcohol, indeed, only . At the very least, the theoretical limits on energy yield are determined to be to . It is also important to note that step 1 on this reaction is endothermic, requiring of alcohol, or about 3 molecules of adenosine triphosphate (ATP) per molecule of ethanol.
|
|
Edwards, in addition, also partook in a study that assessed the extent to which the body responds to lacking amounts of necessary proteins via intake. The results supported the conclusion that the body compensates for how much protein is added; for example, when the minimal protein intake was met, the body responded by conserving methionine catabolism. And additionally, when certain amino acids were lacking, they were synthesized as well as reused, in lieu of excretion. Edwards concluded overall that around 46 grams of protein a day are required in the continued maintenance of the adult male.
|
|
The sulfates are excreted in the urine. Due to its effects similar to nitric oxide (without its potential to form peroxides by interacting with superoxide), hydrogen sulfide is now recognized as potentially protecting against cardiovascular disease. The cardioprotective role effect of garlic is caused by catabolism of the polysulfide group in allicin to , a reaction that could depend on reduction mediated by glutathione. Though both nitric oxide (NO) and hydrogen sulfide have been shown to relax blood vessels, their mechanisms of action are different: while NO activates the enzyme guanylyl cyclase, activates ATP- sensitive potassium channels in smooth muscle cells.
|
|
Thus, the Box and Paa pathways illustrate the prevalence of non-oxygenolytic ring-cleavage strategies in aerobic aromatic degradation processes. Functional genomic studies have been useful in establishing that even organisms harboring high numbers of homologous enzymes seem to contain few examples of true redundancy. For example, the multiplicity of ring-cleaving dioxygenases in certain rhodococcal isolates may be attributed to the cryptic aromatic catabolism of different terpenoids and steroids. Finally, analyses have indicated that recent genetic flux appears to have played a more significant role in the evolution of some large genomes, such as LB400's, than others.
|
|
This is the role that Hod plays in magic, while the music and dance that may be present in such a ceremony is the role that Netzach might play, providing the raw energy to reach the higher levels of consciousness. In comparison with Eastern systems, both Hod and Netzach are sometimes associated with the Manipura chakra, which is associated with the breaking down and releasing of energy, anabolism and catabolism. In 777, Aleister Crowley associates Hod to the Four Eights of occult tarot, Anubis, Thoth, Hanuman, Loki, Hermes, Mercury, Jackal. Hermaphrodite, Opal, Storax, and quicksilver (Not a complete list).
|
|
The presence of gyrate atrophy with iminoglycinuria stems from a deficiency of proline in chorioretinal tissues, while processes behind hyperornithinemia disrupt the metabolic pathway from ornithine to proline, which alters the catabolism of ornithine, and also results in reduced levels of proline. Thus, gyrate atrophy can be found with either disorder, with proline deficiency as an underlying feature. Hyperglycinuria is another disorder affecting reabsorption of glycine and imino acids, similar to iminoglycinuria and considered to be a heterozygous form. When accompanied by a specific type of kidney stone (nephrolithiasis), it is sometimes referred to as "iminoglycinuria, type II".
|
|
The frequent hyperactivation of mTOR (mammalian target of rapamycin) signaling has also been observed in epithelioid sarcoma. The mTOR pathway has been described as a “master switch” for cellular catabolism and anabolism, and it can enhance cell cycle progression, cell survival, and block normal cell death (apoptosis). It has been demonstrated that simply blocking mTOR signaling can result in the reactivation of the AKT pathway, negating much of the anti-mTOR's efficacy. This reactivation of AKT has been shown to be c-MET-dependent, resulting in the rationale that blocking both mTOR and c-MET concurrently would show increased efficacy.
|
|
The cell determines whether the amphibolic pathway will function as an anabolic or catabolic pathway by enzyme–mediated regulation at a transcriptional and post-transcriptional level. As many reactions in amphibolic pathways are freely reversible or can be bypassed, irreversible steps that facilitate their dual function are necessary. The pathway uses a different enzyme for each direction for the irreversible step in the pathway, allowing independent regulation of catabolism and anabolism. Due their inherent duality, amphibolic pathways represent the regulation modes of both anabolic by its negative feedback end product and catabolic by feedback by energy indicator sequences.
|
|
Abnormalities in BCKD activity often leads to pathological conditions which is why BCKDK is needed to regulate it. Often, mutations in the BCKDK gene occur creating the deviation in BCKD behavior. Exceedingly high BCKD complex activity increases branched-chain amino acid catabolism and protein degradation in skeletal muscle, which is a distinctive feature for cachexia. Deficiencies in BCKD activity have been the main cause in the rare metabolism maple syrup urine disease that can lead to mental retardation, brain edema, seizures, coma, and death if not treated correctly by lifelong limitation of branched-chain amino acid intake.
|
|
A functional single- nucleotide polymorphism (a common normal variant) of the gene for catechol-O- methyltransferase results in a valine to methionine mutation at position 158 (Val158Met) rs4680. In vitro, the homozygous Val variant metabolizes dopamine at up to four times the rate of its methionine counterpart. However, in vivo the Met variant is overexpressed in the brain, resulting in a 40% decrease (rather than 75% decrease) in functional enzyme activity. The lower rates of catabolism for the Met allele results in higher synaptic dopamine levels following neurotransmitter release, ultimately increasing dopaminergic stimulation of the postsynaptic neuron.
|
|
GLUD1 (glutamate dehydrogenase 1) is a mitochondrial matrix enzyme, one of the family of glutamate dehydrogenases that are ubiquitous in life, with a key role in nitrogen and glutamate (Glu) metabolism and energy homeostasis. This dehydrogenase is expressed at high levels in liver, brain, pancreas and kidney, but not in muscle. In the pancreatic cells, GLUD1 is thought to be involved in insulin secretion mechanisms. In nervous tissue, where glutamate is present in concentrations higher than in the other tissues, GLUD1 appears to function in both the synthesis and the catabolism of glutamate and perhaps in ammonia detoxification.
|
|
The biological breakdown (catabolism) of VWF is largely mediated by the enzyme ADAMTS13 (acronym of "a disintegrin-like and metalloprotease with thrombospondin type 1 motif no. 13"). It is a metalloproteinase that cleaves VWF between tyrosine at position 842 and methionine at position 843 (or 1605–1606 of the gene) in the A2 domain. This breaks down the multimers into smaller units, which are degraded by other peptidases. The half-life of vWF in human plasma is around 16 hours; glycosylation variation on vWF molecules from different individuals result in a larger range of 4.2 to 26 hours.
|
|
Some non-proteinogenic amino acids are not found in proteins. Examples include 2-aminoisobutyric acid and the neurotransmitter gamma-aminobutyric acid. Non- proteinogenic amino acids often occur as intermediates in the metabolic pathways for standard amino acids – for example, ornithine and citrulline occur in the urea cycle, part of amino acid catabolism (see below). A rare exception to the dominance of α-amino acids in biology is the β-amino acid beta alanine (3-aminopropanoic acid), which is used in plants and microorganisms in the synthesis of pantothenic acid (vitamin B5), a component of coenzyme A.
|
|
Biotin is a coenzyme for five carboxylases in the human body (propionyl-CoA carboxylase, methylcrotonyl-CoA carboxylase, pyruvate carboxylase, and 2 forms of acetyl-CoA carboxylase.) Therefore, biotin is essential for amino acid catabolism, gluconeogenesis, and fatty acid metabolism. Biotin is also necessary for gene stability because it is covalently attached to histones. Biotinylated histones play a role in repression of transposable elements and some genes. Normally, the amount of biotin in the body is regulated by dietary intake, biotin transporters (monocarboxylate transporter 1 and sodium-dependent multivitamin transporter), peptidyl hydrolase biotinidase (BTD), and the protein ligase holocarboxylase synthetase.
|
|
The range is wide because of normal variations due to protein intake, endogenous protein catabolism, state of hydration, hepatic urea synthesis, and renal urea excretion. A BUN of 15 mg/dl would represent significantly impaired function for a woman in the thirtieth week of gestation. Her higher glomerular filtration rate (GFR), expanded extracellular fluid volume, and anabolism in the developing fetus contribute to her relatively low BUN of 5 to 7 mg/dl. In contrast, the rugged rancher who eats in excess of 125 g protein each day may have a normal BUN of 20 mg/dl.
|
|
In enzymology, a dihydropyrimidine dehydrogenase (NADP+) () is an enzyme that catalyzes the chemical reaction :5,6-dihydrouracil + NADP+ \rightleftharpoons uracil + NADPH + H+ Thus, the two substrates of this enzyme are 5,6-dihydrouracil and NADP+, whereas its 3 products are uracil, NADPH, and H+. In humans the enzyme is encoded by the DPYD gene. It is the initial and rate- limiting step in pyrimidine catabolism. It catalyzes the reduction of uracil and thymine. It is also involved in the degradation of the chemotherapeutic drugs 5-fluorouracil and tegafur.. It also participates in beta-alanine metabolism and pantothenate and coa biosynthesis.
|
|
Large scale protein and fat catabolism usually occur when those suffer from starvation or certain endocrine disorders. The liver regenerates the glucose, using a process called gluconeogenesis. This process is not quite the opposite of glycolysis, and actually requires three times the amount of energy gained from glycolysis (six molecules of ATP are used, compared to the two gained in glycolysis). Analogous to the above reactions, the glucose produced can then undergo glycolysis in tissues that need energy, be stored as glycogen (or starch in plants), or be converted to other monosaccharides or joined into di- or oligosaccharides.
|
|
The frequency of marginal biotin status is not known, but the incidence of low circulating biotin levels in alcoholics has been found to be much greater than in the general population. Also, relatively low levels of biotin have been reported in the urine or plasma of patients who have had a partial gastrectomy or have other causes of achlorhydria, burn patients, epileptics, elderly individuals, and athletes. Pregnancy and lactation may be associated with an increased demand for biotin. In pregnancy, this may be due to a possible acceleration of biotin catabolism, whereas, in lactation, the higher demand has yet to be elucidated.
|
|
PAH is a critical enzyme in phenylalanine metabolism and catalyzes the rate-limiting step in its complete catabolism to carbon dioxide and water. Regulation of flux through phenylalanine-associated pathways is critical in mammalian metabolism, as evidenced by the toxicity of high plasma levels of this amino acid observed in phenylketonuria (see below). The principal source of phenylalanine is ingested proteins, but relatively little of this pool is used for protein synthesis. Instead, the majority of ingested phenylalanine is catabolized through PAH to form tyrosine; addition of the hydroxyl group allows for the benzene ring to be broken in subsequent catabolic steps.
|
|
Long chain fatty acids (more than 14 carbon) need to be converted to fatty acyl-CoA in order to pass across the mitochondria membrane. Fatty acid catabolism begins in the cytoplasm of cells as acyl-CoA synthetase uses the energy from cleavage of an ATP to catalyze the addition of coenzyme A to the fatty acid. The resulting acyl-CoA cross the mitochondria membrane and enter the process of beta oxidation. The main products of the beta oxidation pathway are acetyl-CoA (which is used in the citric acid cycle to produce energy), NADH and FADH.
|
|
LAMP1 and LAMP2 glycoproteins comprise 50% of all lysosomal membrane proteins, and are thought to be responsible in part for maintaining lysosomal integrity, pH and catabolism. The expression of LAMP1 and LAMP2 glycoproteins are linked, as deficiencies in LAMP1 gene will lead to increased expression of LAMP2 glycoproteins. The two are therefore thought to share similar functions in vivo. However, this makes the determining the precise function of LAMP1 difficult, because while the LAMP1 deficient phenotype is little different than the wild type due to LAMP2 up regulation, the LAMP1/LAMP2 double deficient phenotype leads to embryonic lethality.
|
|
They perform key roles in lipid metabolism and the conversion of reactive oxygen species. Peroxisomes are involved in the catabolism of very long chain fatty acids, branched chain fatty acids, bile acid intermediates (in the liver), D-amino acids, and polyamines, the reduction of reactive oxygen species – specifically hydrogen peroxide. – and the biosynthesis of plasmalogens, i.e., ether phospholipids critical for the normal function of mammalian brains and lungs They also contain approximately 10% of the total activity of two enzymes (Glucose-6-phosphate dehydrogenase and 6-Phosphogluconate dehydrogenase) in the pentose phosphate pathway , which is important for energy metabolism.
|
|
Globoid cell leukodystrophy PAS - Multinucleated macrophages ("globoid cells") and loss of myelinated fibers in a case of Krabbe's leukodystrophy Like MLD, Krabbe disease is another type of leukodystrophy with autosomal recessive inheritance that is the result of a lysosomal storage disorder. It is due to a deletion in exon 16 of the GALC gene that causes a frameshift mutation leading to a premature stop codon. The GALC gene, found on chromosome 14 at position 31 (14q31), codes for the enzyme beta- galactocerebrosidase (GALC). GALC is a lysosomal enzyme responsible for the catabolism of galactolipids, especially psychosine, that are heavily distributed throughout the brain.
|
|
Females then attach their eggs to the undersides of rocks in caves or crevices, where they hatch within three to five months. S. apama is semelparous, and death follows shortly after a single mating cycle and laying of eggs that will spawn the next generation. S. apama has poor anaerobic capability compared to most aquatic invertebrates and a lack of food leads to catabolism. Stomach-content analysis indicates fasting during the breeding season, and as S. apama can catabolise no more than 50% of its body weight, it slowly loses physical condition as the season progresses and eventually dies.
|
|
NAD is important in catabolism of fat, carbohydrate, protein, and alcohol, as well as cell signaling and DNA repair, and NADP mostly in anabolism reactions such as fatty acid and cholesterol synthesis. Vitamin intake recommendations made by several countries are that intakes of 14–18 mg/day are sufficient to meet the needs of healthy adults. Niacin or nicotinamide (niacinamide) are used for prevention and treatment of pellagra, a disease caused by lack of the vitamin. When niacin is used as a medicine to treat elevated cholesterol and triglycerides, daily doses range from 500 to 3,000 mg/day.
|
|
Oxidative deamination is a form of deamination that generates α-keto acids and other oxidized products from amine-containing compounds, and occurs only in the liver. Oxidative deamination is an important step in the catabolism of amino acids, generating a more metabolizable form of the amino acid, and also generating ammonia as a toxic byproduct. The ammonia generated in this process can then be neutralized into urea via the urea cycle. Much of the oxidative deamination occurring in cells involves the amino acid glutamate, which can be oxidatively deaminated by the enzyme glutamate dehydrogenase (GDH), using NAD or NADP as a coenzyme.
|
|
As a doctoral student, Bernheim was aware of the limited research which had been conducted on the catabolism of tyramine, a naturally occurring monoamine compound obtained from the amino acid tyrosine. Keeping in mind the availability of newly enhanced techniques for the analysis of oxidative processes, she decided to study the manner in which the addition of tyramine affected oxygen uptake in tissues. During the course of her work, Bernheim used rabbit liver extracts and obtained the enzyme by adding kaolin to the liver extracts at pH 6.5. Following this, crude tyramine was procured by heating tyrosine in the presence of the catalyst diphenylamine.
|
|
Allopurinol was first synthesized and reported in 1956 by Roland K. Robins (1926-1992), in a search for antineoplastic agents. Because allopurinol inhibits the breakdown (catabolism) of the thiopurine drug mercaptopurine, and it was later tested by Wayne Rundles, in collaboration with Gertrude Elion's lab at Wellcome Research Laboratories to see if it could improve treatment of acute lymphoblastic leukemia by enhancing the action of mercaptopurine. However, no improvement in leukemia response was noted with mercaptopurine- allopurinol co-therapy, so that work turned to other compounds and the team then started testing allopurinol as a potential for gout. Allopurinol was first marketed as a treatment for gout in 1966.
|
|
Due to a lack of lysine catabolism, the amino acid accumulates in plasma and patients develop hyperlysinaemia, which can present as asymptomatic to severe neurological disabilities, including epilepsy, ataxia, spasticity, and psychomotor impairment. The clinical significance of hyperlysinemia is the subject of debate in the field with some studies finding no correlation between physical or mental disabilities and hyperlysinemia. In addition to this, mutations in genes related to lysine metabolism have been implicated in several disease states, including pyridoxine-dependent epilepsia (ALDH7A1 gene), α-ketoadipic and α-aminoadipic aciduria (DHTKD1 gene), and glutaric aciduria type 1 (GCDH gene). Hyperlysinuria is marked by high amounts of lysine in the urine.
|
|
Aminoacylase-1 is a cytosolic, homodimeric, zinc-binding enzyme that catalyzes the hydrolysis of acylated L-amino acids to L-amino acids and acyl group, and has been postulated to function in the catabolism and salvage of acylated amino acids. ACY1 has been assigned to chromosome 3p21.1, a region reduced to homozygosity in small-cell lung cancer (SCLC), and its expression has been reported to be reduced or undetectable in SCLC cell lines and tumors. The amino acid sequence of human aminoacylase-1 is highly homologous to the porcine counterpart, and ACY1 is the first member of a new family of zinc- binding enzymes.
|
|
In fat catabolism, triglycerides are hydrolyzed to break them into fatty acids and glycerol. In the liver the glycerol can be converted into glucose via dihydroxyacetone phosphate and glyceraldehyde-3-phosphate by way of gluconeogenesis. In many tissues, especially heart and skeletal muscle tissue, fatty acids are broken down through a process known as beta oxidation, which results in the production of mitochondrial acetyl-CoA, which can be used in the citric acid cycle. Beta oxidation of fatty acids with an odd number of methylene bridges produces propionyl-CoA, which is then converted into succinyl-CoA and fed into the citric acid cycle as an anaplerotic intermediate.
|
|
Kelatorphan is a drug which acts as a powerful and complete inhibitor of nearly all of the enzymes responsible for catabolism of the endogenous enkephalins, including neutral endopeptidase (NEP), dipeptidyl peptidase III (DPP3), aminopeptidase N (APN), and angiotensin-converting enzyme (ACE). In mice, with the intracerebroventricular co-administration of a 50 µg dose of kelatorphan (this route is necessary because kelatorphan is incapable of crossing the blood-brain-barrier) hence alongside exogenous [Met]enkephalin (ED50 approximately 10 ng), it potentiated the analgesic effects of the latter by 50,000 times. Kelatorphan also displays potent antinociceptive effects alone, and does not depress respiration, although at high doses it actually increases it.
|
|
Peroxisome proliferator-activated receptor alpha (PPARα) is a nuclear receptor that functions as a transcription factor. It acts in muscle, adipose tissue, and liver to turn on a set of genes essential for fatty acid oxidation, including the fatty acid transporters carnitine acyltransferases 1 and 2, the fatty acyl–CoA dehydrogenases for short, medium, long, and very long acyl chains, and related enzymes. PPARα functions as a transcription factor in two cases; as mentioned before when there is an increased demand for energy from fat catabolism, such as during a fast between meals or long-term starvation. Besides that, the transition from fetal to neonatal metabolism in the heart.
|
|
In the first, pantethine serves as the precursor for synthesis of coenzyme A. CoA is involved in the transfer of acetyl groups, in some instances to attach to proteins closely associated with activating and deactivating genes. By this theory, either the genes responsible for cholesterol and triglyceride synthesis are suppressed or the genes governing the catabolism of compounds are turned on. In the second theory, pantethine is converted to two pantetheine molecules which are in turn metabolized to form two pantethenic acid and two cysteamine molecules. Cysteamine is theorized to bind to and thus inactivate sulfur-containing amino acids in liver enzymes involved in the production of cholesterol and triglycerides.
|
|
In the late 1960s Tenhunen demonstrated an enzymatic reaction for heme catabolism thereby identifying the heme oxygenase (HO) enzyme. HO is the main source of endogenous CO production, though other minor contributors have been identified in recent years. CO is formed at a rate of 16.4 µmol/hour in the human body, ~86% originating from heme via heme oxygenase and ~14% from non-heme sources including: photooxidation, lipid peroxidation, and xenobiotics. The average carboxyhemoglobin (CO-Hb) level in a non-smoker is between 0.2% and 0.85% CO-Hb (whereas a smoker may have between 4% and 10% CO-Hb), though geographic location, occupation, health and behavior are contributing variables.
|
|
This increases the chances that a mutation that will affect a mitochondrion will occur in chromosomal DNA, which is inherited in a Mendelian pattern. Another result is that a chromosomal mutation will affect a specific tissue due to its specific needs, whether those may be high energy requirements or a need for the catabolism or anabolism of a specific neurotransmitter or nucleic acid. Because several copies of the mitochondrial genome are carried by each mitochondrion (2–10 in humans), mitochondrial mutations can be inherited maternally by mtDNA mutations which are present in mitochondria inside the oocyte before fertilization, or (as stated above) through mutations in the chromosomes.
|
|
I-cell disease is an autosomal recessive disorder caused by a deficiency of GlcNAc phosphotransferase, which phosphorylates mannose residues to mannose-6-phosphate on N-linked glycoproteins in the Golgi apparatus within cells. Without mannose-6-phosphate to target them to the lysosomes, the enzymes are erroneously transported from the Golgi to the extracellular space. Consequently lysosomes lack the requisite hydrolytic enzymes needed for catabolism of cellular debris, so this debris accumulates within them and forms the characteristic intracellular inclusions (hence the name of the disorder). Hydrolases secreted into the blood stream cause little problem as they are inactivate at the near neutral pH of blood (7.4).
|
|
Other experimental methods being researched involve substrate reduction therapy, which attempts to use alternative enzymes to increase the brain's catabolism of GM2 gangliosides to a point where residual degradative activity is sufficient to prevent substrate accumulation. One experiment has demonstrated that using the enzyme sialidase allows the genetic defect to be effectively bypassed, and as a consequence, GM2 gangliosides are metabolized so that their levels become almost inconsequential. If a safe pharmacological treatment can be developed – one that increases expression of lysosomal sialidase in neurons without other toxicity – then this new form of therapy could essentially cure the disease. Another metabolic therapy under investigation for Tay–Sachs disease uses miglustat.
|
|
Inositol oxygenase, also commonly referred to as myo-inositol oxygenase (MIOX), is a non-heme di-iron enzyme that oxidizes myo-inositol to glucuronic acid. The enzyme employs a unique four-electron transfer at its Fe(II)/Fe(III) coordination sites and the reaction proceeds through the direct binding of myo-inositol followed by attack of the iron center by diatomic oxygen. This enzyme is part of the only known pathway for the catabolism of inositol in humans and is expressed primarily in the kidneys. Recent medical research regarding MIOX has focused on understanding its role in metabolic and kidney diseases such as diabetes, obesity and acute kidney injury.
|
|
Metabolic reactions may be categorized as catabolic – the breaking down of compounds (for example, the breaking down of glucose to pyruvate by cellular respiration); or anabolic – the building up (synthesis) of compounds (such as proteins, carbohydrates, lipids, and nucleic acids). Usually, catabolism releases energy, and anabolism consumes energy. The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed through a series of steps into another chemical, each step being facilitated by a specific enzyme. Enzymes are crucial to metabolism because they allow organisms to drive desirable reactions that require energy that will not occur by themselves, by coupling them to spontaneous reactions that release energy.
|
|
APOA5 mainly functions to influence plasma triglyceride levels. The first suggested mechanism supposes that APOA5 functions as an activator of lipoprotein lipase (which is a key enzyme in triglyceride catabolism) and, through this process, enhances the metabolism of TG-rich particles. The second is the possible effect of APOA5 on the secretion of VLDL particles, since APOA5 reduces hepatic production by inhibiting VLDL- particle production and assembly by binding to cellular membranes and lipids. Finally, the third possibility relates to the acceleration of the hepatic uptake of lipoprotein remnants and it has been shown that APOA5 binds to different members of the low-density lipoprotein receptor family.
|
|
The function of fumarase in the citric acid cycle is to facilitate a transition step in the production of energy in the form of NADH. In the cytosol the enzyme functions to metabolize fumarate, which is a byproduct of the urea cycle as well as amino acid catabolism. Studies have revealed that the active site is composed of amino acid residues from three of the four subunits within the tetrameric enzyme. The primary binding site on fumarase is known as catalytic site A. Studies have revealed that catalytic site A is composed of amino acid residues from three of the four subunits within the tetrameric enzyme.
|
|
Beta-mannosidase (, mannanase, mannase, beta-D-mannosidase, beta-mannoside mannohydrolase, exo-beta-D-mannanase, lysosomal beta A mannosidase) is an enzyme with systematic name beta-D-mannoside mannohydrolase, which is in humans encoded by the MANBA gene. This enzyme catalyses the following chemical reaction : Hydrolysis of terminal, non-reducing beta-D-mannose residues in beta-D-mannosides This gene encodes a member of the glycosyl hydrolase 2 family. The encoded protein localizes to the lysosome where it is the final exoglycosidase in the pathway for N-linked glycoprotein oligosaccharide catabolism. Mutations in this gene are associated with beta-mannosidosis, a lysosomal storage disease that has a wide spectrum of neurological involvement.
|
|
Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-Q oxidoreductase), also known as electron transferring-flavoprotein dehydrogenase, is a third entry point to the electron transport chain. It is an enzyme that accepts electrons from electron-transferring flavoprotein in the mitochondrial matrix, and uses these electrons to reduce ubiquinone. This enzyme contains a flavin and a [4Fe–4S] cluster, but, unlike the other respiratory complexes, it attaches to the surface of the membrane and does not cross the lipid bilayer. In mammals, this metabolic pathway is important in beta oxidation of fatty acids and catabolism of amino acids and choline, as it accepts electrons from multiple acetyl-CoA dehydrogenases.
|
|
Once the chylomicrons (or other lipoproteins) travel through the tissues, these particles will be broken down by lipoprotein lipase in the luminal surface of endothelial cells in capillaries to release triglycerides. Triglycerides will get broken down into fatty acids and glycerol before entering cells and remaining cholesterol will again travel through the blood to the liver. Breakdown of fatty acids by beta oxidation In the cytosol of the cell (for example a muscle cell), the glycerol will be converted to glyceraldehyde 3-phosphate, which is an intermediate in the glycolysis, to get further oxidized and produce energy. However, the main steps of fatty acids catabolism occur in the mitochondria.
|
|
Common symptoms of mercury poisoning include peripheral neuropathy, presenting as paresthesia or itching, burning, pain, or even a sensation that resembles small insects crawling on or under the skin (formication); skin discoloration (pink cheeks, fingertips and toes); swelling; and desquamation (shedding or peeling of skin). Mercury irreversibly inhibits selenium-dependent enzymes (see below) and may also inactivate S-adenosyl-methionine, which is necessary for catecholamine catabolism by catechol-O-methyl transferase. Due to the body's inability to degrade catecholamines (e.g. epinephrine), a person suffering from mercury poisoning may experience profuse sweating, tachycardia (persistently faster-than-normal heart beat), increased salivation, and hypertension (high blood pressure).
|
|
Autophagy is essential for basal homeostasis; it is also extremely important in maintaining muscle homeostasis during physical exercise. Autophagy at the molecular level is only partially understood. A study of mice shows that autophagy is important for the ever-changing demands of their nutritional and energy needs, particularly through the metabolic pathways of protein catabolism. In a 2012 study conducted by the University of Texas Southwestern Medical Center in Dallas, mutant mice (with a knock-in mutation of BCL2 phosphorylation sites to produce progeny that showed normal levels of basal autophagy yet were deficient in stress-induced autophagy) were tested to challenge this theory.
|
|
Cometabolism is defined as the simultaneous degradation of two compounds, in which the degradation of the second compound (the secondary substrate) depends on the presence of the first compound (the primary substrate). This is in contrast to simultaneous catabolism, where each substrate is catabolized concomitantly by different enzymes. Cometabolism occurs when an enzyme produced by an organism to catalyze the degradation of its growth-substrate to derive energy and carbon from it is also capable of degrading additional compounds. The fortuitous degradation of these additional compounds does not support the growth of the bacteria, and some of these compounds can even be toxic in certain concentrations to the bacteria.
|
|
Although there are nearly forty different types of leukodystrophies, many are lacking in formal and comprehensive research. Most of the research so far has been done on five types: (1) metachromatic leukodystrophy (MLD), (2) Krabbe disease, (3) X-Linked adrenoleukodystrophy (ALD), (4) Canavan disease, and (5) Alexander disease. Each type of leukodystrophy has a unique pathophysiology, but all five of these in some way affect a subset of glial cells, therefore disrupting myelin production and maintenance, and usually involve a mutation involving genes that code for enzymes necessary for the catabolism of very long chain fatty acids (VLCFAs) that are toxic to the myelin-producing cells of the central nervous system.
|
|
The upregulation of phosphatase genes is significant in that it indicates that a significant portion of the phosphorus obtained by the fungi in some environments may be from organic molecule catabolism. It is important to note that once a mycorrhizal symbiosis is established the only phosphorus obtained by the plant comes through the fungal tissue. Additionally the large scale assisted transport of phosphorus from fungi to plant only occurs when the fungal pelotons are alive, once these structures start to degrade significant flow of phosphorus ceases. This classifies this pathway as biotrophic, meaning transfer of nutrients between two or more organisms that are both alive.
|
|
Glutathione S-transferase Zeta 1 (also known as maleylacetoacetate isomerase) is an enzyme that in humans is encoded by the GSTZ1 gene on chromosome 14. This gene is a member of the glutathione S-transferase (GSTs) super-family, which encodes multifunctional enzymes important in the detoxification of electrophilic molecules, including carcinogens, mutagens, and several therapeutic drugs, by conjugation with glutathione. This enzyme also plays a significant role in the catabolism of phenylalanine and tyrosine. Thus, defects in this enzyme may lead to severe metabolic disorders, including alkaptonuria, phenylketonuria and tyrosinaemia, and new discoveries may allow the enzyme to protect against certain diseases related to oxidative stress.
|
|
T-DNA contains two types of genes: the oncogenic genes, encoding for enzymes involved in the synthesis of auxins and cytokinins and responsible for tumor formation; and the genes encoding for the synthesis of opines. These compounds, produced by condensation between amino acids and sugars, are synthesized and excreted by the crown gall cells and consumed by A. tumefaciens as carbon and nitrogen sources. Outside the T-DNA, are located the genes for the opine catabolism, the genes involved in the process of T-DNA transfer from the bacterium to the plant cell and the genes involved in bacterium-bacterium plasmid conjugative transfer. (Hooykaas and Schilperoort, 1992; Zupan and Zambrysky, 1995).
|
|
In 1969, Dr. Langer returned to Argentina where he was appointed Director of the Institute for Pharmacological Research. The work started in Cambridge continued at the Institute in Buenos Aires during the years 1969-1976, leading to the discovery of the presynaptic inhibitory Alpha-adrenoceptors on noradrenergic nerve terminals and their role in the modulation of the NE release during nerve stimulationPossible physiological significance of the initial step in the catabolism of noradrenaline in the central nervous system of the rat M. B. Farah, E. Adler- Graschinsky, S. Z. Langer: Naunyn-schmiedebergs Archives of Pharmacology - NAUNYN-SCHMIED ARCH PHARMACOL vol. 297, no. 2, pp.
|
|
It processes the blood supplied to it via filtration, reabsorption, secretion and excretion; the consequence of those processes is the production of urine. These include the nitrogenous wastes urea, from protein catabolism, and uric acid, from nucleic acid metabolism. The ability of mammals and some birds to concentrate wastes into a volume of urine much smaller than the volume of blood from which the wastes were extracted is dependent on an elaborate countercurrent multiplication mechanism. This requires several independent nephron characteristics to operate: a tight hairpin configuration of the tubules, water and ion permeability in the descending limb of the loop, water impermeability in the ascending loop, and active ion transport out of most of the ascending limb.
|
|
The characteristics of life Since there is no unequivocal definition of life, most current definitions in biology are descriptive. Life is considered a characteristic of something that preserves, furthers or reinforces its existence in the given environment. This characteristic exhibits all or most of the following traits: # Homeostasis: regulation of the internal environment to maintain a constant state; for example, sweating to reduce temperature # Organization: being structurally composed of one or more cells – the basic units of life # Metabolism: transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
|
|
Although the etiology is unconfirmed, transient hyperammonemia is known to be caused by increased levels of ammonia in the blood stream, as well as a failure of the urea cycle to convert enough of the ammonia into urea. Since transamination of proteins is a leading producer of ammonia, protein restriction may be recommended as a therapy to reduce the symptoms of the episode. THAN can also be treated by avoiding amino acids in TPN or total parenteral nutrition or by giving a high caloric diet to limit catabolism of the tissues and therefore to minimize the breakdown of endogenous protein. The most common treatments are dialysis (both peritoneal and hemodialysis), sodium benzoate, and arginine.
|
|
Methylisocitrate lyase is used in the methylcitrate cycle, a modified version of the Krebs cycle that metabolizes propionyl coenzyme A instead of acetyl coenzyme A. The enzyme 2-methylcitrate synthase adds propionyl coenzyme A to oxaloacetate, yielding methylcitrate instead of citrate. But isomerizing methylcitrate to methylisocitrate and then subjecting it to MICL regenerates succinate, which proceeds as in the Krebs cycle, and pyruvate, which is easily metabolized by other pathways (e.g. decarboxylated to form acetyl coenzyme A and oxidized in the Krebs cycle). This allows catabolism of propionic acid—and, using beta oxidation, other fatty acids with odd numbers of carbons—without relying on coenzyme B12, a complex cofactor often used to metabolize propionate.
|
|
Acyl-CoAs also mediate protein targeting to various membranes and regulation of G Protein α subunits, because they are substrates for protein acylation. In the mitochondria, acyl-CoA esters are involved in the acylation of mitochondrial NAD+ dependent dehydrogenases; because these enzymes are responsible for amino acid catabolism, this acylation renders the whole process inactive. This mechanism may provide metabolic crosstalk and act to regulate the NADH/NAD+ ratio in order to maintain optimal mitochondrial beta oxidation of fatty acids. The role of CoA esters in lipid metabolism and numerous other intracellular processes are well defined, and thus it is hypothesized that ACOT- enzymes play a role in modulating the processes these metabolites are involved in.
|
|
Imbalances in calcium and phosphorus levels can result in various skeletal complications. Excess phosphorus can produce lesions in bones whereas excessive calcium can lead to hypocalcaemia and result in excess bone deposition, interfering with normal bone development. In extreme circumstances of insufficient calcium intake, bone resorption can occur due to the body withdrawing calcium deposits from the skeletal frame as a last resort to fulfill dietary needs. Omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been shown to be highly effective in the prevention of cartilage catabolism in in vitro models, suggesting that its supplementation in food could aid in decreasing the symptoms of osteoarthritis in German shepherds.
|
|
A Chemical and Physical Foundations Thermodynamics and kinetics Redox states Water, pH, acid-base reactions and buffers Solutions and equilibria Solute-solvent interactions Chemical interactions and bonding Chemical reaction mechanisms B Structural Biology: Structure, Assembly, Organization and Dynamics Small molecules Macromolecules (e.g., nucleic acids, polysaccharides, proteins and complex lipids) Supramolecular complexes (e.g., membranes, ribosomes and multienzyme complexes) C Catalysis and Binding Enzyme reaction mechanisms and kinetics Ligand-protein interaction (e.g., hormone receptors, substrates and effectors, transport proteins and antigen-antibody interactions) D Major Metabolic Pathways Carbon, nitrogen and sulfur assimilation Anabolism Catabolism Synthesis and degradation of macromolecules E Bioenergetics (including respiration and photosynthesis) Energy transformations at the substrate level Electron transport Proton and chemical gradients Energy coupling (e.g.
|
|
Cell division, growth & proliferation Cell growth refers to an increase in the total mass of a cell, including both cytoplasmic, nuclear and organelle volume. Cell growth occurs when the overall rate of cellular biosynthesis (production of biomolecules or anabolism) is greater than the overall rate of cellular degradation (the destruction of biomolecules via the proteasome, lysosome or autophagy, or catabolism). Cell growth is not to be confused with cell division or the cell cycle, which are distinct processes that can occur alongside cell growth during the process of cell proliferation, where a cell, known as the "mother cell", grows and divides to produce two "daughter cells". Importantly, cell growth and cell division can also occur independently of one another.
|
|
Acyl-CoAs also mediate protein targeting to various membranes and regulation of G protein α subunits, because they are substrates for protein acylation. In the mitochondria, acyl-CoA esters are involved in the acylation of mitochondrial NAD+ dependent dehydrogenases; because these enzymes are responsible for amino acid catabolism, this acylation renders the whole process inactive. This mechanism may provide metabolic crosstalk and act to regulate the NADH/NAD+ ratio in order to maintain optimal mitochondrial beta oxidation of fatty acids. The role of CoA esters in lipid metabolism and numerous other intracellular processes are well defined, and thus it is hypothesized that ACOT- enzymes play a role in modulating the processes these metabolites are involved in.
|
|
Acyl-CoAs also mediate protein targeting to various membranes and regulation of G Protein α subunits, because they are substrates for protein acylation. In the mitochondria, acyl-CoA esters are involved in the acylation of mitochondrial NAD+ dependent dehydrogenases; because these enzymes are responsible for amino acid catabolism, this acylation renders the whole process inactive. This mechanism may provide metabolic crosstalk and act to regulate the NADH/NAD+ ratio in order to maintain optimal mitochondrial beta oxidation of fatty acids. The role of CoA esters in lipid metabolism and numerous other intracellular processes are well defined, and thus it is hypothesized that ACOT- enzymes play a role in modulating the processes these metabolites are involved in.
|
|
A model microorganism studied for its role in bioremediation of oil-spill sites and hydrocarbon catabolism is the alpha- proteobacteria Alcanivorax, which degrades aliphatic alkanes through various metabolic activities. Alcanivorax borkumensis utilizes linear hydrocarbon chains in petroleum as its primary energy source under aerobic conditions. When further supplied with sufficient limiting nutrients such as nitrogen and phosphor, it grows and produces surfactant glucolipids to help reduce surface water tension and enhance hydrocarbon uptake.[5] For this reason, nitrates and phosphates are often commercially added to oil-spill sites to engage quiescent populations of A. borkumensis, allowing them to quickly outcompete other microbial populations and become the dominant species in the oil-infested environment.
|
|
Acyl-CoAs also mediate protein targeting to various membranes and regulation of G protein α subunits, because they are substrates for protein acylation. In the mitochondria, acyl-CoA esters are involved in the acylation of mitochondrial NAD+ dependent dehydrogenases; because these enzymes are responsible for amino acid catabolism, this acylation renders the whole process inactive. This mechanism may provide metabolic crosstalk and act to regulate the NADH/NAD+ ratio in order to maintain optimal mitochondrial beta oxidation of fatty acids. The role of CoA esters in lipid metabolism and numerous other intracellular processes are well defined, and thus it is hypothesized that ACOT- enzymes play a role in modulating the processes these metabolites are involved in.
|
|
Acyl-CoAs also mediate protein targeting to various membranes and regulation of G Protein α subunits, because they are substrates for protein acylation. In the mitochondria, acyl-CoA esters are involved in the acylation of mitochondrial NAD+ dependent dehydrogenases; because these enzymes are responsible for amino acid catabolism, this acylation renders the whole process inactive. This mechanism may provide metabolic crosstalk and act to regulate the NADH/NAD+ ratio in order to maintain optimal mitochondrial beta oxidation of fatty acids. The role of CoA esters in lipid metabolism and numerous other intracellular processes are well defined, and thus it is hypothesized that ACOT- enzymes play a role in modulating the processes these metabolites are involved in.
|
|
Intermediate depths of the lagoon support facultative micro-organisms capable of oxidizing both the dissolved and suspended organics from the original wastewater and the products of anaerobic catabolism on the bottom of the lagoon.Metcalf & Eddy (1972) pp.552-554 Areas with a consistently cool, but frost-free, climate may sustain facultative conditions in the first stabilization pond when treating lightly polluted water at low temperatures favorable to high concentrations of dissolved oxygen with low metabolic rates. Facultative pond stratification becomes unstable during cold weather increasing release of malodorous gas when water temperatures drop below 4 degrees Celsius (39 degrees Fahrenheit); and formation of ice on the pond surface will effectively prevent transfer of atmospheric oxygen to the pond biome.
|
|
As a member of subfamily 7 of the aldehyde dehydrogenase gene family, antiquitin performs NAD(P)+-dependent oxidation of aldehydes generated by alcohol metabolism, lipid peroxidation, and other cases of oxidative stress, to their corresponding carboxylic acids . In addition, antiquitin plays a role in protecting cells and tissues from the damaging effects of osmotic stress, presumably through the generation of osmolytes. Antiquitin may also play a protective role for DNA in cell growth, as the protein is found to be up-regulated during the G1–S phase transition, which undergoes the highest degree of oxidative stress in the cell cycle. Furthermore, antiquitin functions as an aldehyde dehydrogenase for α-AASA in the pipecolic acid pathway of lysine catabolism.
|
|
Acyl-CoAs also mediate protein targeting to various membranes and regulation of G Protein α subunits, because they are substrates for protein acylation. In the mitochondria, acyl-CoA esters are involved in the acylation of mitochondrial NAD+ dependent dehydrogenases; because these enzymes are responsible for amino acid catabolism, this acylation renders the whole process inactive. This mechanism may provide metabolic crosstalk and act to regulate the NADH/NAD+ ratio in order to maintain optimal mitochondrial beta oxidation of fatty acids. The role of CoA esters in lipid metabolism and numerous other intracellular processes are well defined, and thus it is hypothesized that ACOT- enzymes play a role in modulating the processes these metabolites are involved in.
|
|
AUH is seen to catalyze the transformation of 3-methylglutaconyl-CoA to 3-hydroxy-3-methylglutaryl CoA in the leucine catabolism pathway. Localized in the mitochondria, AUH is responsible for the fifth step in the leucine degradation pathway and deficiencies in this enzyme's activity leads to a metabolic block in which 3-methylglutaconyl-CoA, accumulates in the mitochondrial matrix. Also, these reductions in the enzyme's activity leads to increases in 3-methylglutaric acid and 3-hydroxyisovaleric acid. Another function of AUH is that it binds to an AU-rich element (ARE), containing clusters of the penta-nucleotide AUUUA. AREs have been found in the 3’-untranslated regions of mRNA and they promote mRNA degradation.
|
|
Amino acids from ingested food that are used for the synthesis of proteins and other biological substances — or produced from catabolism of muscle protein — are oxidized by the body as an alternative source of energy, yielding urea and carbon dioxide. The oxidation pathway starts with the removal of the amino group by a transaminase; the amino group is then fed into the urea cycle. The first step in the conversion of amino acids from protein into metabolic waste in the liver is removal of the alpha-amino nitrogen, which results in ammonia. Because ammonia is toxic, it is excreted immediately by fish, converted into uric acid by birds, and converted into urea by mammals.
|
|
GluDH isozymes are generally involved with either ammonia assimilation or glutamate catabolism. Two separate enzymes are present in yeasts: the NADP- dependent enzyme, which catalyses the amination of alpha-ketoglutarate to L-glutamate; and the NAD-dependent enzyme, which catalyses the reverse reaction \- this form links the L-amino acids with the Krebs cycle, which provides a major pathway for metabolic interconversion of alpha-amino acids and alpha-keto acids. Leucine dehydrogenase (LeuDH) is a NAD-dependent enzyme that catalyses the reversible deamination of leucine and several other aliphatic amino acids to their keto analogues. Each subunit of this octameric enzyme from Bacillus sphaericus contains 364 amino acids and folds into two domains, separated by a deep cleft.
|
|
Alcohol flush reaction as a result of the accumulation of acetaldehyde, the first metabolite of alcohol After being ingested, the ethanol in alcoholic beverages is first converted to acetaldehyde by the enzyme alcohol dehydrogenase and then to acetic acid by oxidation and egestion process. These reactions also convert nicotinamide adenine dinucleotide (NAD+) to its reduced form NADH in a redox reaction. By causing an imbalance of the NAD+/NADH redox system, alcoholic beverages make normal bodily functions more difficult. Consequences of the alcohol induced redox changes in the human body include increased triglyceride production, increased amino acid catabolism, inhibition of the citric acid cycle, lactic acidosis, ketoacidosis, hyperuricemia, disturbance in cortisol and androgen metabolism and increased fibrogenesis.
|
|
One hypothesis is that the increased purine catabolism from placental hypoxia results in increased ROS production in the maternal liver and release into the maternal circulation that causes endothelial cell damage. Abnormalities in the maternal immune system and insufficiency of gestational immune tolerance seem to play major roles in pre-eclampsia. One of the main differences found in pre-eclampsia is a shift toward Th1 responses and the production of IFN-γ. The origin of IFN-γ is not clearly identified and could be the natural killer cells of the uterus, the placental dendritic cells modulating responses of T helper cells, alterations in synthesis of or response to regulatory molecules, or changes in the function of regulatory T cells in pregnancy.
|
|
Oxandrolone, sold under the brand names Oxandrin and Anavar, among others, is an androgen and anabolic steroid (AAS) medication which is used to help promote weight gain in various situations, to help offset protein catabolism caused by long-term corticosteroid therapy, to support recovery from severe burns, to treat bone pain associated with osteoporosis, to aid in the development of girls with Turner syndrome, and for other indications. It is taken by mouth. Side effects of oxandrolone include symptoms of masculinization such as acne, increased hair growth, voice changes, and increased sexual desire. The drug is a synthetic androgen and anabolic steroid, hence is an agonist of the androgen receptor (AR), the biological target of androgens such as testosterone and dihydrotestosterone.
|
|
Although there is no current treatment to correct the abnormal metabolic processes underlying this disease, there are approaches to ameliorate symptoms and decrease the effects of this disease. Because there is an increase of fat storage and a decrease in fat catabolism, low fat diets are recommended for slowing the progression of the disease, including the onset of type 2 diabetes and hypothyroidism. In addition, diets containing triglycerides composed of short chain fatty acids are more beneficial than TGAs containing long chain fatty acids. Ketone bodies can be rapidly transported, catabolized, and used by many tissues including the brain. Medium-chain fatty acids in an individual’s diet are rapidly used by the body, limiting storage and therefore alleviating lipid droplet accumulation.
|
|
The pharmacodynamic action of AAS begin when the exogenous hormone penetrates the membrane of the target cell and binds to an androgen receptor (AR) located in the cytoplasm of that cell. From there, the compound hormone-receptor diffuses into the nucleus, where it either alters the expression of genes or activates processes that send signals to other parts of the cell. Different types of AAS bind to the AAR with different affinities, depending on their chemical structure. The effect of AAS on muscle mass is caused in at least two ways: first, they increase the production of proteins; second, they reduce recovery time by blocking the effects of stress hormone cortisol on muscle tissue, so that catabolism of muscle is greatly reduced.
|
|
In enzymology, a (R)-4-hydroxyphenyllactate dehydrogenase () is an enzyme that catalyzes the chemical reaction :(R)-3-(4-hydroxyphenyl)lactate + NAD(P)+ \rightleftharpoons 3-(4-hydroxyphenyl)pyruvate + NAD(P)H + H The 3 substrates of this enzyme are (R)-3-(4-hydroxyphenyl)lactate, NAD, and NADP, whereas its 4 products are 3-(4-hydroxyphenyl)pyruvate, NADH, NADPH, and H. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH- OH group of donor with NAD or NADP as acceptor. The systematic name of this enzyme class is (R)-3-(4-hydroxyphenyl)lactate:NAD(P) 2-oxidoreductase. Other names in common use include (R)-aromatic lactate dehydrogenase, and D-hydrogenase, D-aryllactate. This enzyme participates in tyrosine and phenylalanine catabolism.
|
|
The biochemical pathways required to utilize glucose as a carbon and energy source are highly conserved from bacteria to humans. PGM1 is an evolutionarily conserved enzyme that regulates one of the most important metabolic carbohydrate trafficking points in prokaryotic and eukaryotic organisms, catalyzing the bi-directional interconversion of glucose 1-phosphate (G-1-P) and glucose 6-phosphate (G-6-P). In one direction, G-1-P produced from sucrose catabolism is converted to G-6-P, the first intermediate in glycolysis. In the other direction, conversion of G-6-P to G-1-P generates a substrate for synthesis of UDP-glucose, which is required for synthesis of a variety of cellular constituents, including cell wall polymers and glycoproteins.
|
|
The cell utilizes this in many energetically difficult oxidation reactions such as dehydrogenation of a C-C bond to an alkene. FAD-dependent proteins function in a large variety of metabolic pathways including electron transport, DNA repair, nucleotide biosynthesis, beta-oxidation of fatty acids, amino acid catabolism, as well as synthesis of other cofactors such as CoA, CoQ and heme groups. One well-known reaction is part of the citric acid cycle (also known as the TCA or Krebs cycle); succinate dehydrogenase (complex II in the electron transport chain) requires covalently bound FAD to catalyze the oxidation of succinate to fumarate by coupling it with the reduction of ubiquinone to ubiquinol. The high-energy electrons from this oxidation are stored momentarily by reducing FAD to FADH2.
|
|
As the cell rises up, it is able to increase its carbohydrate load through increased photosynthesis. Too high and the cell will suffer photobleaching and possible death, however, the carbohydrate produced during photosynthesis increases the cell's density, causing it to sink. The daily cycle of carbohydrate build-up from photosynthesis and carbohydrate catabolism during dark hours is enough to fine-tune the cell's position in the water column, bring it up toward the surface when its carbohydrate levels are low and it needs to photosynthesis, and allowing it to sink away from the harmful UV radiation when the cell's carbohydrate levels have been replenished. An extreme excess of carbohydrate causes a significant change in the internal pressure of the cell, which causes the gas vesicles to buckle and collapse and the cell to sink out.
|
|
Sunlight is also captured by plants as a chemical potential energy via photosynthesis, when carbon dioxide and water are converted into a combustible combination of carbohydrates, lipids, and oxygen. The release of this energy as heat and light may be triggered suddenly by a spark, in a forest fire; or it may be available more slowly for animal or human metabolism when these molecules are ingested, and catabolism is triggered by enzyme action. Through all of these transformation chains, the potential energy stored at the time of the Big Bang is later released by intermediate events, sometimes being stored in several different ways for long periods between releases, as more active energy. All of these events involve the conversion of one kind of energy into others, including heat.
|
|
The feed-forward loop in the arabinose utilization systems of E.coli delays the activation of arabinose catabolism operon and transporters, potentially avoiding unnecessary metabolic transition due to temporary fluctuations in upstream signaling pathways. Similarly in the Wnt signaling pathway of Xenopus, the feed-forward loop acts as a fold-change detector that responses to the fold change, rather than the absolute change, in the level of β-catenin, potentially increasing the resistance to fluctuations in β-catenin levels. Following the convergent evolution hypothesis, the enrichment of feed-forward loops would be an adaptation for fast response and noise resistance. A recent research found that yeast grown in an environment of constant glucose developed mutations in glucose signaling pathways and growth regulation pathway, suggesting regulatory components responding to environmental changes are dispensable under constant environment.
|
|
The discovery that a hormone can influence phosphoinositide metabolism was made by Mabel R. Hokin (1924–2003) and her then husband Lowell E. Hokin in 1953, when they discovered that radioactive 32P phosphate was incorporated into the phosphatidylinositol of pancreas slices when stimulated with acetylcholine. Up until then phospholipids were believed to be inert structures only used by cells as building blocks for construction of the plasma membrane. Over the next 20 years, little was discovered about the importance of PIP2 metabolism in terms of cell signaling, until the mid-1970s when Robert H. Michell hypothesized a connection between the catabolism of PIP2 and increases in intracellular calcium (Ca2+) levels. He hypothesized that receptor-activated hydrolysis of PIP2 produced a molecule that caused increases in intracellular calcium mobilization.
|
|
The organs mainly involved in heme synthesis are the liver (in which the rate of synthesis is highly variable, depending on the systemic heme pool) and the bone marrow (in which rate of synthesis of Heme is relatively constant and depends on the production of globin chain), although every cell requires heme to function properly. However, due to its toxic properties, proteins such as Hemopexin (Hx) are required to help maintain physiological stores of iron in order for them to be used in synthesis. Heme is seen as an intermediate molecule in catabolism of hemoglobin in the process of bilirubin metabolism. Defects in various enzymes in synthesis of heme can lead to group of disorder called porphyrias, these include acute intermittent porphyria, congenital erythropoetic porphyria, porphyria cutanea tarda, hereditary coproporphyria, variegate porphyria, erythropoietic protoporphyria.
|
|
HMG-CoA reductase (3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, officially abbreviated HMGCR) is the rate-controlling enzyme (NADH-dependent, ; NADPH-dependent, ) of the mevalonate pathway, the metabolic pathway that produces cholesterol and other isoprenoids. Normally in mammalian cells this enzyme is suppressed by cholesterol derived from the internalization and degradation of low density lipoprotein (LDL) via the LDL receptor as well as oxidized species of cholesterol. Competitive inhibitors of the reductase induce the expression of LDL receptors in the liver, which in turn increases the catabolism of plasma LDL and lowers the plasma concentration of cholesterol, which is considered, by those who accept the standard lipid hypothesis, an important determinant of atherosclerosis. This enzyme is thus the target of the widely available cholesterol-lowering drugs known collectively as the statins.
|
|
The T-DNA fragment is flanked by 25-bp direct repeats, which act as a cis element signal for the transfer apparatus. The process of T-DNA transfer is mediated by the cooperative action of proteins encoded by genes determined in the Ti plasmid virulence region (vir genes) and in the bacterial chromosome. The Ti plasmid also contains the genes for opine catabolism produced by the crown gall cells, and regions for conjugative transfer and for its own integrity and stability. The 30 kb virulence (vir) region is a regulon organized in six operons that are essential for the T-DNA transfer (virA, virB, virD, and virG) or for the increasing of transfer efficiency (virC and virE) (Hooykaas and Schilperoort, 1992; Zupan and Zambryski, 1995, Jeon et al.
|
|
Too high and the cell will suffer photobleaching and possible death, however, the carbohydrate produced during photosynthesis increases the cell's density, causing it to sink. The daily cycle of carbohydrate build-up from photosynthesis and carbohydrate catabolism during dark hours is enough to fine-tune the cell's position in the water column, bring it up toward the surface when its carbohydrate levels are low and it needs to photosynthesis, and allowing it to sink away from the harmful UV radiation when the cell's carbohydrate levels have been replenished. An extreme excess of carbohydrate causes a significant change in the internal pressure of the cell, which causes the gas vesicles to buckle and collapse and the cell to sink out. Large vacuoles are found in three genera of filamentous sulfur bacteria, the Thioploca, Beggiatoa and Thiomargarita.
|
|
4-Hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors (HPPD inhibitors) are a class of herbicides that prevent plants by blocking 4-Hydroxyphenylpyruvate dioxygenase, an enzyme in plants that breaks down the amino acid tyrosine into molecules that are then used by plants to create other molecules that plants need. This process of breakdown, or catabolism, and making new molecules from the results, or biosynthesis, is something all living things do. HPPD inhibitors were first brought to market in 1980, although their mechanism of action was not understood until the late 1990s. They were originally used primarily in Japan in rice production, but since the late 1990s have been used in Europe and North America for corn, soybeans, and cereals, and since the 2000s have become more important as weeds have become resistant to glyphosate and other herbicides.
|
|
In creature tissues, the antecedent glucosylceramide is moved by the sphingolipid transport protein FAPP2 to the distal Golgi, where it should initially cross from the cytosolic side of the membrane conceivably by means of the activity of a flippase. Biosynthesis of lactosylceramide then includes expansion of the second monosaccharides unit as its actuated nucleotide subordinate (UDP-galactose) to monoglucosylceramide on the lumenal side of the Golgi apparatus in a response catalyzed by β-1,4-galactosyltransferases of which two are known. The lactosylceramide created can be further glycosylated, or it very well may be moved to the plasma layer essentially by a non- vesicular system that is inadequately seen, however it can't be translocated back to the cytosolic flyer. It is likewise recovered by the catabolism of a considerable lot of the lipids for which it is the biosynthetic antecedent.
|
|
Arginine is a conditionally essential amino acid in humans and rodents, as it may be required depending on the health status or lifecycle of the individual. For example, while healthy adults can supply their own requirement for arginine, immature and rapidly growing individuals require arginine in their diet, and it is also essential under physiological stress, for example during recovery from burns, injury, and sepsis, or when the small intestine and kidneys, which are the major sites of arginine biosynthesis, have been damaged. It is, however, an essential amino acid for birds, as they do not have a urea cycle. For some carnivores, for example cats, dogs and ferrets, arginine is essential, because after a meal, their highly efficient protein catabolism produces large quantities of ammonia which need to be processed through the urea cycle, and if not enough arginine is present, the resulting ammonia toxicity can be lethal.
|
|
The body invests some of this ATP in gluconeogenesis to produce more glucose.Zechner, R, Kienesberger, PC, Haemmerle, G, Zimmermann, R and Lass, A (2009) Adipose triglyceride lipase and the lipolytic catabolism of cellular fat stores, J Lipid Res, 50, 3-21 Triglycerides and long-chain fatty acids are too hydrophobic to cross into brain cells, so the liver must convert them into short-chain fatty acids and ketone bodies through ketogenesis. The resulting ketone bodies, acetoacetate and β-hydroxybutyrate, are amphipathic and can be transported into the brain (and muscles) and broken down into acetyl-CoA for use in the TCA cycle. Acetoacetate breaks down spontaneously into acetone, and the acetone is released through the urine and lungs to produce the “acetone breath” that accompanies prolonged fasting. The brain also uses glucose during starvation, but most of the body’s glucose is allocated to the skeletal muscles and red blood cells.
|
|
Phosphorylation of sugars is often the first stage in their catabolism. Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism because many sugars are first converted to glucose before they are metabolized further. The chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by :D-glucose + ATP → D-glucose-6-phosphate + ADP :ΔG° = −16.7 kJ/mol (° indicates measurement at standard condition) Researcher D. G. Walker of the University of Birmingham determined the presence of two specific enzymes in adult guinea pig liver, both of which catalyze the phosphorylation of glucose to glucose 6 phosphate. The two enzymes have been identified as a specific glucokinase (ATP-D-glucose 6-phosphotransferase) and non-specific hexokinase (ATP-D-hexose 6-phosphotransferase).
|
|
Lopinavir was developed by Abbott in an attempt to improve upon the company's earlier protease inhibitor, ritonavir, specifically with regard to its serum protein-binding properties (reducing the interference by serum on protease enzyme inhibition) and its HIV resistance profile (reducing the ability of virus to evolve resistance to the drug). Administered alone, lopinavir has insufficient bioavailability; however, like several HIV protease inhibitors, its blood levels are greatly increased by low doses of ritonavir, a potent inhibitor of intestinal and hepatic cytochrome P450 3A4, which would otherwise reduce drug levels through catabolism. Abbott, therefore, pursued a strategy of co-administering lopinavir with doses of ritonavir sub-therapeutic with respect to HIV inhibition; hence, lopinavir was only formulated and marketed as a fixed-dose combination medication with ritonavir. Lopinavir/ritonavir was approved by the US Food and Drug Administration (FDA) on 15 September 2000, and in Europe on 19 March 2001.
|
|
Despite the different experimental conditions, also the proteomic study seems to support the hypothesis that the accumulation of triacylglycerols is due to an increase of the metabolic flux through the fatty acid biosynthetic pathway. The authors advance the hypothesis that, in their experimental conditions, the degradation of storage sugars and the up- regulation of glycolysis are responsible for the increase of substrates through the pathway. More recently Li and coworkers (2014) collected extensive experimental data from cultures of Nannochloropsis oculata IMET1 grown in nitrogen sufficient and nitrogen depleted media. According to their analysis it is the catabolism of carbohydrates and proteins together with the up- regulation of genes assigned to various pathways (the cytosolic glycolysis pathway, which produces pyruvate; the PDHC bypass, which yields additional acetyl-CoA; and the coupling of TCA reactions with mitochondrial β-oxidation) that have to be claimed for increasing the supply of carbon precursors to the fatty acid biosynthetic pathway.
|
|
Glycine cleavage In plants, animals and bacteria the glycine cleavage system catalyzes the following reversible reaction: : Glycine + H4folate + NAD+ ↔ 5,10-methylene-H4folate + CO2 \+ NH3 \+ NADH + H+ In the enzymatic reaction, H-protein activates the P-protein, which catalyzes the decarboxylation of glycine and attaches the intermediate molecule to the H-protein to be shuttled to the T-protein. The H-protein forms a complex with the T-protein that uses tetrahydrofolate and yields ammonia and 5,10-methylenetetrahydrofolate. After interaction with the T-protein, the H-protein is left with two fully reduced thiol groups in the lipoate group. The glycine protein system is regenerated when the H-protein is oxidized to regenerate the disulfide bond in the active site by interaction with the L-protein, which reduces NAD+ to NADH and H+. When coupled to serine hydroxymethyltransferase, the glycine cleavage system overall reaction becomes: : 2 glycine + NAD+ \+ H2O → serine + CO2 \+ NH3 \+ NADH + H+ In humans and most vertebrates, the glycine cleavage system is part of the most prominent glycine and serine catabolism pathway.
|
|
CYP4F11 is active in metabolism of many drugs including benzphetamine, ethylmorphine, chlorpromazine, imipramine, and erythromycin;. The cytochrome is also able to hydroxylate short-chain and 3-hydroxylated medium chain fatty acidss by attaching a hydroxyl residue to their terminal carbon by omega oxidation in a reaction that may be critical to the processing of these fatty acids. It likewise omega-hydroxylates Vitamin Ks including menaquinone in a metabolic step which is essential for their further metabolism by beta oxidation and probably thereby their removal by catabolism to regulate their tissue levels. CYP4F11 omega-hydroxylates leukotriene B4 (LTB4) to 20-hydroxy-LTB4, 5-Hydroxyicosatetraenoic acid (5-HETE) to 20-hydroxy-5-HETE (i.e. 5,20-diHETE), 12-hydroxyeicosatetraenoic acid (12-HETE) to 12,20-diHETE, lipoxins and possibly 5-oxo-eicosatetraenoic acid (5-oxo-ETE) to their 20-hydroxy metabolites; these reactions begin the inactivation of these pro- (LTB4, 5-HETE, 12-HETE, and 5-oxo-ETE) and anti- (lipoxins) cell signaling agents; however, it is relatively weak compared to, and therefore possibly not as physiologically relevant as, other CYP4Fs such as CYP4F2, CYP4F3a, CYP4F3b, CYP4A11 and CYP4F2 in doing so.
|
|