In enzymology, an oligopeptide-transporting ATPase () is an enzyme that catalyzes the chemical reaction :ATP + H2O + oligopeptide(out) \rightleftharpoons ADP + phosphate + oligopeptide(in) The 3 substrates of this enzyme are ATP, H2O, and oligopeptide, whereas its 3 products are ADP, phosphate, and oligopeptide. This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides to catalyse transmembrane movement of substances. The systematic name of this enzyme class is ATP phosphohydrolase (oligopeptide-importing). This enzyme is also called oligopeptide permease.
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Clicked peptide polymers are poly-triazole-poly-peptide hybrid polymers. They are made of repeating units of a 1,2,3-triazole and an oligopeptide. They can be visualized as an oligopeptide that is flanked at both the C-terminus and N-terminus by a triazole molecule.
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Oligopeptide classes are produced by nonribosomal peptides synthases (NRPS), except cyclamides and microviridins are synthesized through ribosomic pathways.
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The molecules linked to one another by the azide-alkyne Huisgen cycloaddition are connected by an aromatic triazole which is extremely stable, and can withstand high temperatures and extremes of pH. The oligopeptide units of a clicked peptide polymer are a different story. The triazole bridges do not confer any stability to oligopeptide. Degradation of the polymer occurs at the peptide bonds linking individual amino acids.
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Some antibacterial drugs such as penicillin interfere with the production of peptidoglycan by binding to bacterial enzymes known as penicillin-binding proteins or DD- transpeptidases. Penicillin-binding proteins form the bonds between oligopeptide crosslinks in peptidoglycan. For a bacterial cell to reproduce through binary fission, more than a million peptidoglycan subunits (NAM- NAG+oligopeptide) must be attached to existing subunits. Mutations in genes coding for transpeptidases that lead to reduced interactions with an antibiotic are a significant source of emerging antibiotic resistance.
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Thiostrepton is a natural cyclic oligopeptide antibiotic of the thiopeptide class, derived from several strains of streptomycetes, such as Streptomyces azureus and Streptomyces laurentii. Thiostrepton is a natural product of the ribosomally synthesized and post-translationally modified peptide (RiPP) class.
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She completed a master's degree in 1991, and in 1996 completed a doctorate at the Institute of Cytology and Genetics of the Russian Academy of Sciences in Nobosibirsk. Her work at the institute involved the design of synthetic oligonucleotides and, separately, the use of oligopeptide frequency data to classify proteins.
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The augmentation of PP secretion has been observed in hormonal-active pancreatic tumors (insulin, glucagon), in Verner-Morrison syndrome, and in gastrinomas. The PPY gene encodes an unusually short protein precursor that is cleaved to produce PP, as well as pancreatic icosapeptide and a 5- to 7- amino-acid oligopeptide.
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Angiotensin is a peptide hormone that causes vasoconstriction and an increase in blood pressure. It is part of the renin–angiotensin system, which regulates blood pressure. Angiotensin also stimulates the release of aldosterone from the adrenal cortex to promote sodium retention by the kidneys. An oligopeptide, angiotensin is a hormone and a dipsogen.
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2\. Shindea UA, Sharma G, Xu YJ, Dhalla NS, Goyal RK: Insulin sensitising action of chromium picolinate in various experimental models of diabetes mellitus. J Trace Elem Med Biol 18: 23–32, 2004 3\. Davis CM, Vincent JB: Chromium oligopeptide activates insulin receptor tyrosine kinase activity. Biochemistry 36: 4382–4385, 1997 4\.
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Proteins of the Proton-dependent Oligopeptide Transporter (POT) Family (also called the PTR (peptide transport) family) are found in animals, plants, yeast, archaea and both Gram-negative and Gram-positive bacteria, and are part of the major facilitator superfamily. The transport of peptides into cells is a well-documented biological phenomenon which is accomplished by specific, energy-dependent transporters found in a number of organisms as diverse as bacteria and humans. The proton-dependent oligopeptide transporter (PTR) family of proteins is distinct from the ABC-type peptide transporters and was uncovered by sequence analyses of a number of recently discovered peptide transport proteins. These proteins that seem to be mainly involved in the intake of small peptides with the concomitant uptake of a proton.
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Ceruletide (INN), also known as cerulein or caerulein, is a ten amino acid oligopeptide that stimulates smooth muscle and increases digestive secretions. Ceruletide is similar in action and composition to cholecystokinin. It stimulates gastric, biliary, and pancreatic secretion; and certain smooth muscle. It is used in paralytic ileus and as diagnostic aid in pancreatic malfunction.
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Peptide transporter 1 (PepT 1) also known as solute carrier family 15 member 1 (SLC15A1) is a protein that in humans is encoded by SLC15A1 gene. PepT 1 is a solute carrier for oligopeptides. It functions in renal oligopeptide reabsorption and in the intestines in a proton dependent way, hence acting like a cotransporter.
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To prepare and oligopeptide with both a terminal azide and terminal alkyne two modifications must be carried out. The first is the amidation of the oligopeptide's C-terminus by propargylamine. This would done with all other reaction groups protected and with the C-terminus activated. Amidation of an tripeptide's C-terminus by propargyl amine.
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P11-4 is a synthetic, pH controlled self-assembling peptide used for biomimetic mineralization e.g. for enamel regeneration or as an oral care agent. P11-4 (INCI name Oligopeptide 104) consists of the natural occurring amino acids Glutamine, Glutamic acid, Phenylalanine, Tryptophan and Arginine. The resulting higher molecular structure has a high affinity to tooth mineral.
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Subsequent protein isolations in rats, dogs, mice and cows have shown the presence of a similar substance, suggesting that it is found extensively in mammals. This oligopeptide is small, having a molecular weight of around 1 500 g/mol and the predominant amino acids present are glutamic acid, glycine, and cysteine. Despite recent efforts to characterize the exact structure of chromodulin, it is still relatively unknown.
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Low-molecular-weight chromium-binding substance (LMWCr; also known as chromodulin) is an oligopeptide that seems to transport chromium in the body. It consists of four amino acid residues; aspartate, cysteine, glutamate, and glycine, bonded with four (Cr3+) centers. It interacts with the insulin receptor, by prolonging kinase activity through stimulating the tyrosine kinase pathway, thus leading to improved glucose absorption. and has been confused with glucose tolerance factor.
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The KX Blood-group Antigen (KXA) Family (TC# 2.A.112) consists of transport proteins that are part of the TOG superfamily. The KX gene codes for a novel protein with characteristics of membrane transporters that has been proposed to be a Na+ -dependent neutral amine and/or oligopeptide transporter. It is predicted to be 444 amino acyl residues in length and exhibits 10 putative transmembrane α-helical segments.
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Both receptor types bind and are activated by a series of formylated oligopeptide chemotactic factors but FLP2 receptor appears to be a promiscuous receptor in that it also binds to and is activated by lipoxins and resolvins as well as various polypeptides and proteins. The FLP2 receptor appears to be engaged primarily in dampening and resolving inflammation responses, actions which appear to be diametrically opposite to the pro-inflammatory actions of FLP1 receptors.
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Genes for ABC transporters are also identified that are likely to be responsible for oligopeptide uptake, indicating that TM7 cells are capable of using other amino acids also. There is evidence of a base substitution in the 16S rRNA genes, which is highly atypical, and is associated with antibiotic resistance against streptomycin. On the consensus 16S rRNA, on position 912, C is substituted with U and this is linked to resistance against streptomycin.
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When the insulin signaling pathway is turned off, the insulin receptors on the plasma membrane relax and become inactivated. The holo-LMWCr is expelled from the cell and ultimately excreted from the body via urine. LMWCr cannot be converted back into its inactive from due to the high binding affinity of this oligopeptide for its chromium ions. As of currently, the mechanism through which apo-LMWCr is replaced within the body is unknown.
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These short homologous repeating units have been termed combined repetitive oligopeptide (CROPs). A recent study demonstrates that the CROPs determine the potency of TcdA through interactions with structures on the cell surface. These CROP regions range from 21-50 residues and play a role in receptor binding. This C-terminal repetitive region is designated as the immuno-dominant region since ligand binding can be blocked by monoclonal antibodies specific to this region.
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A tetrapeptide, a hetero-oligomer of the amino acids valine (green), glycine (black), serine (black), and alanine (blue). The units were joined by condensation of the carboxylic acid group –C(=O)OH of one monomer with the amine group of the next one. Some biologically important oligomers consist of macromolecules like proteins or nucleic acids; for instance, hemoglobin is a protein tetramer. An oligomer of amino acids is called an oligopeptide or just a peptide.
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The Sup35p protein is 685 amino acids long. The C-terminal contains 5 complete and one incomplete repeat of the Oligopeptide repeat sequence PQGGYQQ-YN. In modified versions of the gene, it has been shown that the more repeats of this sequence present, the more the protein is to assume the [Psi+] confirmation. In fact, the addition of two extra repeats (R2) result in the [Psi-] to [Psi+] conversion in being 5000 times faster.
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Several draft genomes from whole genome sequencing have been published. C.auris has a genome size of 12.3–12.5 Mb with a GC-content of 44.5–44.8%. The C.auris genome was found to encode several genes for the ABC transporter family, a major facilitator superfamily, which helps to explain its multiple drug resistance. Its genome also encodes virulence-related gene families such as lipases, oligopeptide transporters, mannosyl transferases and transcription factors which facilitate colonization, invasion, and iron acquisition.
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Widely distributed in mammals, LMWCr is capable of tightly binding four chromic ions. The binding constant of this oligopeptide for chromium ions is very large, (K ≈ 1021 M−4), suggesting it is strong and tightly binding. LMWCr exists in its inactive or apo form within the cytosol and nucleus of insulin-sensitive cells. When insulin concentrations within the blood rise, insulin binds to the external subunit of the insulin-receptor proteins, and induces a conformational change.
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Bezlotoxumab is a human monoclonal antibody designed for the prevention of recurrence of Clostridium difficile infections. By x-ray crystallized structure of N-terminal of TcdB, the toxin is identified to consist of three domains: a glucosyltransferase domain (GTD), a cysteine protease and a combined repetitive oligopeptide (CROP) domain. Bezlotoxumab specifically binds to two homologous sites within the CROP domain of TcdB. Structural analysis by X-ray crystallography indicates that antibody binding partially occludes putative carbohydrate binding pockets.
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In order to mimic a mature bone matrix, self-assembled fibrils can be used to align a given mineral matrix. This is accomplished using a self- assembling molecule with a hydrophobic alkyl tail and a hydrophilic oligopeptide head. These molecules form micellar structures in situ, and disulfide bridges at low pH, leading to the formation and crystallization of 200 kDa polymeric nanofibrils. The mineral matrix ultimately interacts with the synthetic fibril via a phosphoserine residue which results in mineral nucleation and growth.
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Renal oligopeptide reabsorption is the part of renal physiology that deals with the retrieval of filtered oligopeptides, preventing them from disappearing from the body through the urine. Almost all reabsorption takes place in the proximal tubule. Practically nothing is left in the final urine. Longer oligopeptides, such as angiotensin and glutathione are degraded by enzymes on the brush border, while shorter ones, such as carnosine, are transported across the apical membrane as a whole by the PepT 1 transporter, and degraded inside the proximal tubule cell.
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This diagram shows the insulin pathway and its role in regulating blood glucose levels Low-molecular- weight chromium-binding substance (LMWCr; also known as chromodulin) is an oligopeptide that seems to bind chromium(III) in the body. It consists of four amino acid residues; aspartate, cysteine, glutamate, and glycine, bonded with four (Cr3+) centers. It interacts with the insulin receptor, by prolonging kinase activity through stimulating the tyrosine kinase pathway, thus leading to improved glucose absorption. It has been confused with glucose tolerance factor.
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Antipain is an oligopeptide that is isolated from actinomycetes and used in biochemical research as a protease inhibitor of trypsin and papain. It was discovered in 1972 and was the first natural peptide found that contained an ureylene group. It has been crystallised in complexes with carboxypeptidase, which is obtained from wheat,PDB ENTRY and Leishmania major oligopeptidase B.PDB ENTRY In both cases, the backbone carbonyl of the terminal arginine of antipain forms a covalent bond to the active site serine in the protease.
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The group, X at the C-terminus can be a normal or activated carboxylate such as an anhydride, acid-chloride, or NHS-ester. The second modification required is the addition of an azide to the N-terminus. Unlike the addition of the alkyne this can be done on the whole peptide, or solely on the N-terminal residue which is added to the rest of the oligopeptide by solid-phase peptide synthesis. The addition of the azide occurs by Cu(II)-catalyzed diazo transfer.
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Some studies suggest that the biologically active form of chromium (III) is transported in the body via an oligopeptide called low-molecular-weight chromium-binding substance (LMWCr), which might play a role in the insulin signaling pathway. Chromium content of common foods is generally low (1-13 micrograms per serving). Chromium content of food varies widely due to differences in soil mineral content, growing season, plant cultivar, and contamination during processing. In addition, chromium (and nickel) leach into food cooked in stainless steel, with the effect largest when the cookware is new.
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Some amino acids contain the opposite absolute chirality, chemicals that are not available from normal ribosomal translation/transcription machinery. Most bacterial cells walls are formed by peptidoglycan, a polymer composed of amino sugars crosslinked with short oligopeptides bridged between each other. The oligopeptide is non-ribosomally synthesised and contains several peculiarities including D-amino acids, generally D-alanine and D-glutamate. A further peculiarity is that the former is racemised by a PLP-binding enzymes (encoded by alr or the homologue dadX), whereas the latter is racemised by a cofactor independent enzyme (murI).
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The prototypical fMet-containing oligopeptide is N-Formylmethionine-leucyl-phenylalanine (FMLP) which activates leukocytes and other cell types by binding with these cells' formyl peptide receptor 1 (FPR1) and formyl peptide receptor 2 (FPR2) G protein coupled receptors (see also formyl peptide receptor 3). Acting through these receptors, the fMet-containing oligopeptides and proteins are part of the innate immune system; they function to initiate acute inflammation responses but under other conditions function to inhibit and resolve these responses. fMet-containing oligopeptides and proteins also function in other physiological and pathological responses.
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The mode of action through which chromium aided in the regulation of blood glucose levels is poorly understood. Recently, it has been suggested that chromium interacts with the low-molecular weight chromium (LMWCr) binding substance to potentiate the action of insulin. LMWCr has a molecular weight of 1500, and is composed solely of the four amino acid residues of glycine, cysteine, aspartic acid and glutamate. It is a naturally occurring oligopeptide that has been purified from many sources: rabbit liver, porcine kidney and kidney powder, bovine liver, colostrum, dog, rat and mouse liver.
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Thus, bacteria produce a family of oligopeptide chemotactic factors plus activate host complement pathways to generate C5a, which, like the formylated oligopeptides, is a neutrophil chemotactic factor that operates through receptors whose genes cluster with those for the three formly peptide receptors. Furthermore, bacteria-induced complement activation also causes the formation of complement component 3a (C3a) by cleavage from complement component 3; C3a is a neutrophil chemotactic factor which operates through a G protein coupled chemotactic factor receptor, the C3a receptor, whose gene is located at chromosome 12p13; C3a also acts through C5L2.
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ThermoQuest AvantGarde MS with quadrupole detector and FAB/EI source. The first example of the practical application of this FAB was the elucidation of the amino acid sequence of the oligopeptide efrapeptin D. This contained a variety of very unusual amino acid residues.Bullough,D.A., Jackson C.G.,Henderson, P.J.F., Cottee, F.H.,Beechey,R.B. and Linnett, P.E. Biochemistry International (1981) 4, 543-549 The sequence was shown to be: N-acetyl-L-pip-AIB-L-pip-AIB-AIB-L-leu-beta-ala-gly-AIB-AIB-L-pip-AIB-gly-L- leu-L-iva-AIB-X.
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The SHP's are translated to an immature form of the pheromone and must undergo processing, first by a metalloprotease enzyme inside the cell and then in the extracellular space, to reach their mature active form. The mode of transportation out of the cell and the extracellular processing factor(s) are still unknown. The mature SHP pheromone can then be taken into nearby cells and the cell it originated from via a transmembrane protein, oligopeptide permease. In the cytosol the pheromones have two functions in the Rgg2/3 pathway.
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Boletus edulis is known to be able to tolerate and even thrive on soil that is contaminated with toxic heavy metals, such as soil that might be found near metal smelters. The mushroom's resistance to heavy-metal toxicity is conferred by a biochemical called a phytochelatin—an oligopeptide whose production is induced after exposure to metal. Phytochelatins are chelating agents, capable of forming multiple bonds with the metal; in this state, the metal cannot normally react with other elements or ions and is stored in a detoxified form in the mushroom tissue.
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In vitro and animal studies[1,2] have shown chromium to have a positive effect on insulin sensitivity. One of the intracellular proteins influencing the insulin receptor is the oligopeptide apolipoprotein, low molecular weight, chromium-binding substance (apo- chromomodulin) [2]. In vitro, this peptide has the ability to increase tyrosine kinase activity eightfold, depending on the chromium concentration [3]. This in turn promotes insulin receptor activity, thus eliciting improved insulin sensitivity. Therefore, for some time now, chromium has been thought to play a beneficial role in glucose metabolism and, as early as 1957, was referred to as a “glucose tolerance factor” [4].
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The binding of HLA-DO at the MHC class II peptide-exchange catalysis site suggested that it acts as a competitive inhibitor, although biochemical studies have established its complementary function to HLA-DM in fine tuning epitope selection. During infection, exogenous antigen is internalized by phagocytosis or receptor-mediated endocytosis, and processed in hydrolytic enzyme-containing compartments of increasing acidity. To bind to the MHC-class II protein, HLA-DM catalyzes the exchange of CLIP, a protein occupying the binding groove of MHC class II, with the antigenic oligopeptide. HLA-DO is strongly associated with HLA-DM throughout the catalyzed exchange.
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Val-Gly-Ala) with green marked amino end (L-Valine) and blue marked carboxyl end (L-Alanine) Val-Gly-Ser-Ala) with green marked amino end (L-valine) and blue marked carboxyl end (L-alanine) An oligopeptide, often just called peptide (oligo-, "a few"), consists of two to twenty amino acids and can include dipeptides, tripeptides, tetrapeptides, and pentapeptides. Some of the major classes of naturally occurring oligopeptides include aeruginosins, cyanopeptolins, microcystins, microviridins, microginins, anabaenopeptins, and cyclamides. Microcystins are best studied, because of their potential toxicity impact in drinking water. A review of some oligopeptides found that the largest class are the cyanopeptolins (40.1%), followed by microcystins (13.4%).
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N-Formylmethionyl-leucyl-phenylalanine (fMLF, fMLP or N-formyl-met-leu-phe) is an N-formylated tripeptide and sometimes simply referred to as chemotactic peptide is a potent polymorphonuclear leukocyte (PMN) chemotactic factor and is also a macrophage activator. fMLF is the prototypical representative of the N-formylated oligopeptide family of chemotactic factors. These oligopeptides are known to be, or mimic the actions of, the N-formyl oligopeptides that are (a) released by tissue bacteria, (b) attract and activate circulating blood leukocytes by binding to specific G protein coupled receptors on these cells, and (c) thereby direct the inflammatory response to sites of bacterial invasion. fMLF is involved in the innate immunity mechanism for host defense against pathogens.
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S-tag is the name of an oligopeptide derived from pancreatic ribonuclease A (RNase A). If RNase A is digested with subtilisin, a single peptide bond is cleaved, but the resulting two products remain weakly bound to each other and the protein, called ribonuclease S, remains active although each of the two products alone shows no enzymatic activity. The N-terminus of the original RNase A, also called S-peptide, consists of 20 amino acid residues, of which only the first 15 are required for ribonuclease activity. This 15 amino acids long peptide is called S15 or S-tag. The amino acid sequence of the S-tag is: Lys-Glu-Thr-Ala-Ala-Ala-Lys-Phe-Glu-Arg-Gln-His-Met-Asp-Ser.
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Genes encoding proteases, cellulose and lignin digestive enzymes, as well as oligopeptide and carbohydrate transporters are upregulated in the mycelial soil webs to facilitate increased carbon uptake. Further more the fungi which mycoheterotrophically interact with orchid plants are often also found in mycorrhizal association with beech trees, and translocation of photosynthate from tree to fungus and then to orchid has been proposed, but a thorough study is still lacking. Once acquired by the fungus the carbon is either converted into sugars, trehalose being extremely common for most mycorrhizal fungus, amino acids, or simply assimilated into the fungal organism. The transfer of carbon from fungi to plant happens in one of two forms either as carbohydrates primarily trehalose, but glucose and sucrose may also be involved, or as an amino acids primarily as arginine but glycine and glutamine can also be transferred.
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Through most of its early period of study, acute inflammatory responses were regarded as self-limiting innate immune system reactions to invading foreign organisms, tissue injuries, and other insults. These reactions were orchestrated by various soluble signaling agents such as a) foreign organism-derived N-formylated oligopeptide chemotactic factors (e.g. N-formylmethionine-leucyl-phenylalanine); b) complement components C5a and C3a which are chemotactic factors formed during the activation of the host's blood complement system by invading organisms or injured tissues; and c) host cell- derived pro-inflammatory cytokines (e.g. interleukin 1s), host-derived pro- inflammatory chemokines (e.g. CXCL8, CCL2, CCL3, CCL4, CCL5, CCL11, CXCL10), platelet-activating factor, and PUFA metabolites including in particular leukotrienes (e.g. LTB4), hydroxyeicosatetraenoic acids (e.g., 5-HETE, 12-HETE), the hydroxylated heptadecatreineoic acid, 12-HHT, and oxoeicosanoids (e.g. 5-oxo-ETE). These agents functioned as pro-inflammatory signals by increasing the permeability of local blood vessels; activating tissue-bound pro-inflammatory cells such as mast cells, and macrophages; and attracting to nascent inflammatory sites and activating circulating neutrophils, monocytes, eosinophils, gamma delta T cells, and Natural killer T cells.
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