42 Sentences With "opioid peptide" | Random Sentence Generator

Also present was a lipase, a digestive enzyme, "similar" to those found in scorpions, and an opioid peptide.

But we actually have three other types of opioid receptors, respectively called delta, kappa, and the more recently discovered nociception opioid peptide receptor (NOP).

Bovine β-casomorphin 7, a casomorphin, has seven amino acids in its peptide sequence. Casomorphin is an opioid peptide (protein fragment) derived from the digestion of the milk protein casein.

Structural correlation between met-enkephalin, an opioid peptide, (left) and morphine, an opiate drug, (right) Opioid peptides are peptides that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Such peptides may be produced by the body itself, for example endorphins. The effects of these peptides vary, but they all resemble those of opiates. Brain opioid peptide systems are known to play an important role in motivation, emotion, attachment behaviour, the response to stress and pain, and the control of food intake.

Exorphins are exogenous opioid peptides, distinguished from endorphins (or endogenous opioid peptides). Exorphins include opioid food peptides like Gluten exorphin and microbial opioid peptides and any other opioid peptide foreign to a host that have metabolic efficacy for that host.

Dense-core vesicle storage is characteristic of opioid peptides storage. The first clues to the functionality of dynorphins came from Goldstein et al. in their work with opioid peptides. The group discovered an endogenous opioid peptide in the porcine pituitary that proved difficult to isolate.

The frogs generate many different pharmacologically active peptides as part of the defensive secretions covering their skin. Several of these peptides have found scientific uses as research ligands, including the opioid peptide dermorphin.Bogdanich, W. and R. R. Ruiz. Turning to Frogs for Illegal Aid in Horse Races.

Thus, dynorphin may cause overeating when a high-fat diet is available. Morley & Levine were the first to describe the role of opioid peptides in stress- related eating. In their study, mice had their tails pinched (causes stress), which induced eating. Stress-related eating was reduced by injecting naloxone, an opioid peptide antagonist.

Leumorphin, also known as dynorphin B1–29, is a naturally occurring endogenous opioid peptide. Derived as a proteolytic cleavage product of residues 226-254 of prodynorphin (preproenkephalin B), leumorphin is a nonacosapeptide (29 amino acids in length) and has the sequence Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Gln- Phe-Lys-Val-Val-Thr-Arg-Ser-Gln-Glu-Asp-Pro-Asn-Ala-Tyr-Ser-Gly-Glu-Leu-Phe- Asp-Ala. It can be further reduced to dynorphin B (dynorphin B-13) and dynorphin B-14 by pitrilysin metallopeptidase 1 (formerly referred to as "dynorphin-converting enzyme"), an enzyme of the endopeptidase family. Leumorphin behaves as a potent and selective κ-opioid receptor agonist, similarly to other endogenous opioid peptide derivatives of prodynorphin.

DPDPE ([-2,-5]enkephalin) is a synthetic opioid peptide and a selective agonist of the δ-opioid receptor (DOR) which is used in scientific research. It was developed in the early 1980s and was the first highly selective agonist of the DOR to be developed. It was derived from structural modification of met-enkephalin.

Dynorphin B, also known as rimorphin, is a form of dynorphin and an endogenous opioid peptide with the amino acid sequence Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Gln- Phe-Lys-Val-Val-Thr. Dynorphin B is generated as a proteolyic cleavage product of leumorphin, which in turn is a cleavage product of preproenkephalin B (prodynorphin).

By sequencing the first 13 amino acids of the peptide, they created a synthetic version of the peptide with a similar potency to the natural peptide. Goldstein et al. applied the synthetic peptide to the guinea ileum longitudinal muscle and found it to be an extraordinarily potent opioid peptide. The peptide was called dynorphin (from the Greek dynamis=power) to describe its potency.

Gliadorphin (also known as gluteomorphin) is an opioid peptide that is formed during digestion of the gliadin component of the gluten protein. It is usually broken down into amino acids by digestion enzymes. It has been hypothesized that children with autism have abnormal leakage from the gut of this compound. This is partly the basis for the gluten-free, casein-free diet.

Stein C, Schäfer M, Machelska H (2003) Attacking pain at its source: new perspectives on opioids. Nature Med;9(8):1003-1008. . Since inflammatory pain is blunted by endogenous opioid peptides activating such peripheral opioid receptors,Busch-Dienstfertig M, Stein C (2010) Opioid receptors and opioid peptide-producing leukocytes in inflammatory pain-basic and therapeutic aspects. Brain Behav. Immun. 24(5):683-694. .

Structural correlation between met-enkephalin, an opioid peptide, (left) and morphine, an opiate drug, (right) An opioidergic agent (or drug) is a chemical which functions to directly modulate the opioid neuropeptide systems (i.e., endorphin, enkephalin, dynorphin, nociceptin) in the body or brain. Examples include opioid analgesics such as morphine and opioid antagonists such as naloxone. Opioidergics also comprise allosteric modulators and enzyme affecting agents like enkephalinase inhibitors.

The properties of the 27-residue peptide are presumably similar to those of amidorphin, although this has not been adequately tested. In some brain areas, amidorphin is extensively further reduced into smaller fragments, such as the non-opioid peptide amidorphin-(8-26), or in humans, amidorphin-8-27. Cleavage of amidorphin into these smaller fragments releases the N-terminal [Met]-enkephalin sequence of amidorphin.

Civelli was born in Fribourg, Switzerland. He received his undergraduate and Ph.D. degrees at the Swiss Federal Institute of Technology in Zurich. The research for his thesis was done at the Institut Jacques Monod in Paris under the supervision of Klaus Scherrer. He then worked as postdoctoral fellow on the discovery of opioid peptide precursors at the University of Oregon, Eugene, with Edward Herbert.

The unusual venom, which targets the body's opioid receptors, is being investigated as a potential new painkiller for human use. The venom consists of a neuropeptide also seen in cone snail venom, a lipase similar to the one used by certain species of scorpions and an opioid peptide. Blennies use it to stun predators. The venom reduces the blood pressure of the predator, relaxing its jaws so the blenny can escape.

DAMGO ([D-Ala2, N-MePhe4, Gly-ol]-enkephalin) is a synthetic opioid peptide with high μ-opioid receptor specificity. It was synthesized as a biologically stable analog of δ-opioid receptor-preferring endogenous opioids, leu- and met-enkephalin. The crystal structure of DAMGO bound to the µ opioid receptor reveals a very similar binding pose to morphinans. Its structure is H-Tyr-D- Ala-Gly-N-MePhe-Gly-ol.

5'-Guanidinonaltrindole (5'-GNTI) is an opioid antagonist used in scientific research which is highly selective for the κ opioid receptor. It is 5x more potent and 500 times more selective than the commonly used κ-opioid antagonist norbinaltorphimine. It has a slow onset and long duration of action, and produces antidepressant effects in animal studies. It also increases allodynia by interfering with the action of the κ-opioid peptide dynorphin.

DADLE ([D-Ala2, D-Leu5]-Enkephalin) is a synthetic opioid peptide with analgesic properties. Although it is often considered a selective delta opioid receptor agonist, it also binds to the μ1 subtype of mu opioid receptors. Treatment with DADLE results in transient depression of mean arterial blood pressure and heart rate.Online Medical Dictionary, enkephalin, leucine-2-alanine Its peptide sequence is Tyr-D-Ala-Gly-Phe-D-Leu.

Opioid peptides are known to play a role in emotion and motivation. The content of β-endorphin (β-EP), an endogenous opioid peptide, has been found to decrease (in varying amounts/brain region) post ovariectomy in female rats within the hypothalamus, hippocampus, and pituitary gland. Such a change in β-EP levels could be the cause of mood swings, behavioral disturbances, and hot flashes in post menopausal women.

Met-enkephalin, also known as metenkefalin (INN), sometimes referred to as opioid growth factor (OGF), is a naturally occurring, endogenous opioid peptide that has opioid effects of a relatively short duration. It is one of the two forms of enkephalin, the other being leu-enkephalin. The enkephalins are considered to be the primary endogenous ligands of the δ-opioid receptor, due to their high potency and selectivity for the site over the other endogenous opioids.

Dynorphin A is a dynorphin, an endogenous opioid peptide with the amino acid sequence: Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys. Dynorphin A1–8 is a truncated form of dynorphin A with the amino acid sequence: Tyr-Gly-Gly- Phe-Leu-Arg-Arg-Ile. Dynorphin A1–8 is an agonist at the mu-, kappa-, and delta-opioid receptors; it has the highest binding affinity for the kappa- opioid receptor.

The blockade of opioid receptors is the basis behind naltrexone's action in the management of opioid dependence--it reversibly blocks or attenuates the effects of opioids. Its mechanism of action in alcohol dependence is generated via κ-opioid receptor antagonism, which blocks the actions of the endogenous opioid peptide dynorphin. Dynorphin typically instates drug-seeking behavior when it binds to the κ-opioid receptor, as well as decreasing dopaminergic signalling in the nucleus accumbens.

Active and inactive μ-opioid receptors The μ-opioid receptors (MOR) are a class of opioid receptors with a high affinity for enkephalins and beta- endorphin, but a low affinity for dynorphins. They are also referred to as μ(mu)-opioid peptide (MOP) receptors. The prototypical μ-opioid receptor agonist is morphine, the primary psychoactive alkaloid in opium. It is an inhibitory G-protein coupled receptor that activates the Gi alpha subunit, inhibiting adenylate cyclase activity, lowering cAMP levels.

Leu-enkephalin is an endogenous opioid peptide neurotransmitter with the amino acid sequence Tyr-Gly-Gly-Phe-Leu that is found naturally in the brains of many animals, including humans. It is one of the two forms of enkephalin; the other is met-enkephalin. The tyrosine residue at position 1 is thought to be analogous to the 3-hydroxyl group on morphine. Leu-enkephalin has agonistic actions at both the μ- and δ-opioid receptors, with significantly greater preference for the latter.

The KOR is a type of opioid receptor that binds the opioid peptide dynorphin as the primary endogenous ligand (substrate naturally occurring in the body). In addition to dynorphin, a variety of natural alkaloids, terpenes and other synthetic ligands bind to the receptor. The KOR may provide a natural addiction control mechanism, and therefore, drugs that target this receptor may have therapeutic potential in the treatment of addiction. There is evidence that distribution and/or function of this receptor may differ between sexes.

Tynorphin is a synthetic opioid peptide which is a potent and competitive inhibitor of the enkephalinase class of enzymes which break down the endogenous enkephalin peptides. It specifically inactivates dipeptidyl aminopeptidase III (DPP3) with very high efficacy, but also inhibits neutral endopeptidase (NEP), aminopeptidase N (APN), and angiotensin-converting enzyme (ACE) to a lesser extent. It has a pentapeptide structure with the amino acid sequence Val-Val-Tyr-Pro-Trp. Tynorphin was discovered in an attempt to develop an enkephalinase inhibitor of greater potency than spinorphin.

Hemorphin-4 is an endogenous opioid peptide of the hemorphin family which possesses antinociceptive properties and is derived from the β-chain of hemoglobin in the bloodstream. It is a tetrapeptide with the amino acid sequence Tyr-Pro-Trp-Thr. Hemorphin-4 has affinities for the μ-, δ-, and κ-opioid receptors that are in the same range as the structurally related β-casomorphins, although affinity to the κ-opioid receptor is markedly higher in comparison. It acts as an agonist at these sites.

Big dynorphin is an endogenous opioid peptide of the dynorphin family that is composed of both dynorphin A and dynorphin B. Big dynorphin has the amino acid sequence: Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln- Lys-Arg-Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Gln-Phe-Lys-Val-Val-Thr. It has nociceptive and anxiolytic-like properties, as well as effects on memory in mice. Big dynorphin is a principal endogenous agonist at the human kappa- opioid receptor.

Spinorphin is an endogenous, non-classical opioid peptide of the hemorphin family first isolated from the bovine spinal cord (hence the prefix spin-) and acts as a regulator of the enkephalinases, a class of enzymes that break down endogenous the enkephalin peptides. It does so by inhibiting the enzymes aminopeptidase N (APN), dipeptidyl peptidase III (DPP3), angiotensin- converting enzyme (ACE), and neutral endopeptidase (NEP). Spinorphin is a heptapeptide and has the amino acid sequence Leu-Val-Val-Tyr-Pro-Trp-Thr (LVVYPWT). It has been observed to possess antinociceptive, antiallodynic, and anti-inflammatory properties.

Opioid growth factor receptor, also known as OGFr or the ζ-opioid receptor, is a protein which in humans is encoded by the OGFR gene. The protein encoded by this gene is a receptor for opioid growth factor (OGF), also known as [Met(5)]-enkephalin. The endogenous ligand is thus a known opioid peptide, and OGFr was originally discovered and named as a new opioid receptor zeta (ζ). However it was subsequently found that it shares little sequence similarity with the other opioid receptors, and has quite different function.

They found that as drug use escalates, so does the presence of CRF in human cerebrospinal fluid. In rat models, the separate use of CRF inhibitors and CRF receptor antagonists both decreased self-administration of the drug of study. Other studies in this review showed dysregulation of other neuropeptides that affect the HPA axis, including enkephalin which is an endogenous opioid peptide that regulates pain. It also appears that µ-opioid receptors, which enkephalin acts upon, is influential in the reward system and can regulate the expression of stress hormones.

Endomorphin-2 (EM-2) is an endogenous opioid peptide and one of the two endomorphins. It has the amino acid sequence Tyr-Pro-Phe-Phe-NH2. It is a high affinity, highly selective agonist of the μ-opioid receptor, and along with endomorphin-1 (EM-1), has been proposed to be the actual endogenous ligand of this receptor (that is, rather than the endorphins). Like EM-1, EM-2 produces analgesia in animals, but whereas EM-1 is more prevalent in the brain, EM-2 is more prevalent in the spinal cord.

Difelikefalin (INN) (developmental code names CR845, FE-202845), also known as D-Phe-D-Phe-D-Leu-D-Lys-[γ-(4-N-piperidinyl)amino carboxylic acid] (as the acetate salt), is an analgesic opioid peptide acting as a peripherally specific, highly selective agonist of the κ-opioid receptor (KOR). It is under development by Cara Therapeutics as an intravenous agent for the treatment of postoperative pain. An oral formulation has also been developed. Due to its peripheral selectivity, difelikefalin lacks the central side effects like sedation, dysphoria, and hallucinations of previous KOR-acting analgesics such as pentazocine and phenazocine.

Endomorphin-1 (EM-1) (amino acid sequence Tyr-Pro-Trp-Phe-NH2) is an endogenous opioid peptide and one of the two endomorphins. It is a high affinity, highly selective agonist of the μ-opioid receptor, and along with endomorphin-2 (EM-2), has been proposed to be the actual endogenous ligand of the μ-receptor. EM-1 produces analgesia in animals and is equipotent with morphine in this regard. The gene encoding for EM-1 has not yet been identified, and it has been suggested that endomorphins could be synthesized by an enzymatic, non-ribosomal mechanism.

In 1994, Mollereau et al. cloned a receptor that was highly homologous to the classical opioid receptors (OPs) μ-OR (MOP), κ-OR (KOP), and δ-OR (DOP) that came to be known as the Nociceptin Opioid Peptide receptor (NOP). As these “classical” opioid receptors were identified 30 years earlier in the mid-1960s, the physiological and pharmacological characterization of NOP as well as therapeutic development targeting this receptor remain decades behind. Although research on NOP has blossomed into its own sub-field, the lack of widespread knowledge of NOP's existence means that it is commonly omitted from studies that investigate the OP family, despite its promising role as a therapeutic target.

Amidorphin is an endogenous, C-terminally amidated, opioid peptide generated as a cleavage product of proenkephalin A in some mammalian species; in humans and most other species, the peptide is 1 residue longer and is not amidated. Amidorphin is widely distributed in the mammalian brain, with particularly high concentrations found in the striatum, and outside of the brain in adrenal medulla and posterior pituitary. The 26-residue peptide named amidorphin is found in several species including bovine (Bos taurus), sheep (Ovis aries), and pig (Sus scrofa). Humans and commonly studied lab animals (mice, rats) produce a 27-residue peptide that does not have an amidated C-terminal residue; this is due to the absence of a Gly in the precursor sequence and replacement with Ala, which is not a substrate for the amidating enzyme (Peptidyl-glycine alpha-amidating monooxygenase).

The nociceptin opioid peptide receptor (NOP), also known as the nociceptin/orphanin FQ (N/OFQ) receptor or kappa-type 3 opioid receptor, is a protein that in humans is encoded by the OPRL1 (opioid receptor-like 1) gene. The nociceptin receptor is a member of the opioid subfamily of G protein- coupled receptors whose natural ligand is the 17 amino acid neuropeptide known as nociceptin (N/OFQ). This receptor is involved in the regulation of numerous brain activities, particularly instinctive and emotional behaviors. Antagonists targeting NOP are under investigation for their role as treatments for depression and Parkinson's disease, whereas NOP agonists have been shown to act as powerful, non-addictive painkillers in non-human primates. Although NOP shares high sequence identity (~60%) with the ‘classical’ opioid receptors μ-OP (MOP), κ-OP (KOP), and δ-OP (DOP), it possesses little or no affinity for opioid peptides or morphine-like compounds.

Another postulated opioid receptor is the ε opioid receptor. The existence of this receptor was suspected after the endogenous opioid peptide beta-endorphin was shown to produce additional actions that did not seem to be mediated through any of the known opioid receptors. Activation of this receptor produces strong analgesia and release of met-enkephalin; a number of widely used opioid agonists, such as the μ agonist etorphine and the κ agonist bremazocine, have been shown to act as agonists for this effect (even in the presence of antagonists to their more well known targets), while buprenorphine has been shown to act as an epsilon antagonist. Several selective agonists and antagonists are now available for the putative epsilon receptor; however, efforts to locate a gene for this receptor have been unsuccessful, and epsilon-mediated effects were absent in μ/δ/κ "triple knockout" mice, suggesting the epsilon receptor is likely to be either a splice variant derived from alternate post-translational modification, or a heteromer derived from hybridization of two or more of the known opioid receptors.

Mogil and colleagues revealed a number of previously unidentified factors affecting the conclusions drawn from biomedical experiments. In 1996, they demonstrated that the newly discovered orphan opioid peptide, orphanin FQ/nociception, did not produce hyperalgesia as originally reported, but rather was reversing the stress-induced analgesia resulting from the intracerebroventricular injection through which it was administered. In 1999, they showed that different inbred strains of mice displayed very different pain sensitivity. Chief among these methodological confounds was the observation that mice display a stress response to the presence of nearby males of a number of mammalian species, including human male experimenters, calling into question the results of thousands of studies in the animal literature when the sex of the experimenter was not controlled, an animal equivalent to the "sweaty t-shirt study" in humans. This finding led to torrent of media activity, with articles on the finding in The New York Times, National Geographic, The Atlantic, The Economist, The New Yorker, Time, and U.S. News & World Report, among others, and radio appearances on NPR’s Science Friday, BBC World Service’s “Newsday” and CBC’s “As It Happens”.