Met-enkephalin 3D structure, alpha-carbons shown as balls and labeled by residue.[1]
Identifiers
Symbol	PENK
Entrez	5179
HUGO	8831
OMIM	131330
RefSeq	NM_006211
UniProt	P01210
Other data
Locus	Chr. 8 q23-q24

An enkephalin is a pentapeptide involved in regulating nociception in the body. The enkephalins are termed endogenous ligands, or specifically endorphins, as they are internally derived and bind to the body's opioid receptors. Discovered in 1975, two forms of enkephalin were revealed, one containing leucine ("leu"), and the other containing methionine ("met"). Both are products of the proenkephalin gene.^[2]

• Met-enkephalin is Tyr-Gly-Gly-Phe-Met.
• Leu-enkephalin has Tyr-Gly-Gly-Phe-Leu.

Contents 1 Endogenous opioid peptides 2 Enkephalin receptor 3 See also 4 References 5 External links

[edit] Endogenous opioid peptides

There are three well-characterized families of opioid peptides produced by the body: enkephalins, endorphins, and dynorphins. The met-enkephalin peptide sequence is coded for by both the enkephalin gene and the endorphin gene (also known as the POMC gene); the leu-enkephalin peptide sequence is coded for by both the enkephalin gene and the dynorphin gene.^[3]

[edit] Enkephalin receptor

The receptors for enkephalin are the opioid receptors (delta receptor). These are a group of G-protein-coupled receptors, with other opioids as ligands as well. The other endogenous opioids are dynorphins, endorphins, endomorphins, and nociceptin/orphanin FQ. The opioid receptors are ~40% identical to somatostatin receptors (SSTRs).

[edit] See also

• Endorphin
• Opioid peptide
• Racecadotril
• RB-101

[edit] References

[edit] External links

• MeSH Enkephalins
• Physiology at MCG 6/6ch2/s6ch2_36

v · d · ePeptides: neuropeptides Hormones see hormones Opioid peptides Dynorphin Big dynorphin • Dynorphin A • Dynorphin B Endorphin Beta-endorphin • Alpha-endorphin • Gamma-endorphin Enkephalin Met-enkephalin • Leu-enkephalin Others Adrenorphin • Amidorphin · Nociceptin · Opiorphin Other neuropeptides Kinins Bradykinin Tachykinins: mammal (Substance P, Neurokinin A, Neurokinin B) · amphibian (Kassinin, Physalaemin) Neuromedins B · N · S · U Other Angiotensin · Bombesin · Calcitonin gene-related peptide · Carnosine · Cocaine and amphetamine regulated transcript · Delta sleep-inducing peptide · FMRFamide · Galanin · Galanin-like peptide · Gastrin releasing peptide · Neuropeptide S · Neuropeptide Y · Neurophysins · Neurotensin · Pancreatic polypeptide · Pituitary adenylate cyclase activating peptide · RVD-Hpα · VGF B trdu: iter (nrpl/grfl/cytl/horl), csrc (lgic, enzr, gprc, igsr, intg, nrpr/grfr/cytr), itra (adap, gbpr, mapk), calc, lipd; path (hedp, wntp, tgfp+mapp, notp, jakp, fsap, hipp, tlrp)

v · d · eOpioids Opium and Poppy straw derivatives Crude opiate extracts/ whole opium products Compote/Kompot/Polish heroin • Diascordium • B & O Supprettes • Dover's powder • Kendal Black Drop • Laudanum • Mithridate • Opium • Paregoric • Poppy straw concentrate • Poppy tea • Smoking opium • Theriac Natural Opiates Opium Alkaloids see also: Components of Opium Codeine • Morphine • Oripavine • Pseudomorphine • Thebaine Alkaloid Salts Mixtures Pantopon • Papaveretum (Omnopon) • Tetrapon Semisynthetics Morphine Family 2-(p-Nitrophenyl)-4-isopropylmorphine  • 14-Hydroxymorphine • 14β-Hydroxymorphine • 2,4-Dinitrophenylmorphine • 6-Methyldihydromorphine • 6-Methylenedihydrodesoxymorphine • 6-Acetyldihydromorphine/6-Monoacetyldihydromorphine • Acetyldihydromorphine • Azidomorphine • Chlornaltrexamine • Chloroxymorphamine • Dihydrodesoxymorphine (Desomorphine) • Dihydromorphine • Ethyldihydromorphine • Hydromorphinol • Methyldesorphine • N-Phenethylnormorphine • Pseudomorphine • RAM-378 3,6 Diesters of Morphine 6-acetyl-1-iodocodeine • 6-nicotinoyldihydromorphine • Acetylpropionylmorphine • Acetylbutyrylmorphine • Diacetyldihydromorphine (Dihydroheroin, Acetylmorphinol) • Diacetyldibenzoylmorphine • Dibutyrylcodeine • Dibutyrylmorphine • Dibenzoylmorphine • Diformylmorphine • Dipropanoylmorphine • Heroin (Diacetylmorphine) • Nicomorphine • Tetrabenzoylmorphine • Tetrabutyrylmorphine Codeine-Dionine Family 6-Monoacetylcodeine • Benzylmorphine • Codeine methylbromide • Desocodeine • Dimethylmorphine (Methocodeine) • Dihydroethylmorphine • Methyldihydromorphine (Dihydroheterocodeine) • Ethylmorphine (Dionine) • Heterocodeine • Isocodeine • Isopropylmorphine • Morpholinylethylmorphine (Pholcodine) • Myrophine • Nalodeine • Transisocodeine Morphinones & Morphols 1-Bromohydrocodone • 1-Bromooxycodone • 1-Chlorohydrocodone • 1-Chlorooxycodone • 1-Iodohydrocodone • 1-Iodooxycodone • 14-Cinnamoyloxycodeinone • 14-Ethoxymetopon • 14-Methoxymetopon • 14β-Hydroxymorphone • 14-Hydroxymorphone • 14-O-Methyloxymorphone • 14-Phenylpropoxymetopon • 7-Spiroindanyloxymorphone • 8,14-Dihydroxydihydromorphinone • Acetylcodone • Acetylmorphone • α-hydrocodol • Bromoisopropropyldihydromorphinone • Codeinone • Codorphone • Codol • Codoxime • Thebacon (Acetyldihydrocodeinone / Dihydrocodeinone enol acetate) • Ethyldihydromorphinone • Hydrocodol • Hydrocodone • Hydromorphinone • Hydromorphol • Hydromorphone • Hydroxycodeine • Isopropropyldihydrocodeinone • Isopropropyldihydromorphinone • Methyldihydromorphinone • Metopon • Morphenol • Morphinol • Morphinone • Morphol • N-Phenethyl-14-ethoxymetopon • Oxycodone • Oxymorphol • Oxymorphinol • Oxymorphone • Pentamorphone • Semorphone Morphides α-chlorocodide (Alphachlorocodide/Chlorocodide)  • α-chloromorphide • 3-Bromomorphide • Bromocodide • Bromomorphide (8-Bromomorphide) • Chlorocodide • Chloromorphide •  • Codide • Fluorocodide (8-Fluorocodide) • Fluormorphide  • Iodocodide  • Iodomorphide (8-Iodomorphide)  • Morphide Dihydrocodeine Series 14-hydroxydihydrocodeine • Acetyldihydrocodeine • Dihydrocodeine • Dihydrodesoxycodeine/Desocodeine • Dihydroisocodeine • Nicocodeine • Nicodicodeine Nitrogen Morphine Derivatives 1-Nitrocodeine • 2-Nitrocodeine • 1-Nitromorphine • 2-Nitromorphine • Codeine-N-Oxide • Heroin-N-Oxide • Hydromorphone-N-Oxide • Morphine-N-Oxide Hydrazones Acetylmorphazone • Hydromorphazone • Morphazone • Oxymorphazone  Halogenated Morphine Derivatives 1-Bromocodeine • 2-Bromocodeine • 1-Bromodiacetylmorphine • 2-Bromodiacetylmorphine • 1-Bromodihydrocodeine • 2-Bromodihydrocodeine • 1-Bromodihydromorphine • 2-Bromodihydromorphine • 1-Bromomorphine • 2-Bromomorphine • 1-Chlorocodeine • 2-Chlorocodeine • 1-Chlorodiacetylmorphine • 2-Chlorodiacetylmorphine • 1-Chlorodihydrocodeine • 2-Chlorodihydrocodeine • 1-Chlorodihydromorphine • 2-Chlorodihydromorphine • 1-Chloromorphine • 2-Chloromorphine • 1-Fluorocodeine • 2-Fluorocodeine • 1-Fluorodiacetylmorphine • 2-Fluorodiacetylmorphine • 1-Fluorodihydrocodeine • 2-Fluorodihydrocodeine • 1-Fluorodihydromorphine • 2-Fluorodihydromorphine • 1-Fluoromorphine • 2-Fluoromorphine • 3-Fluoromorphine • 1-Iodocodeine • 2-Iodocodeine • 1-Iododiacetylmorphine • 2-Iododiacetylmorphine • 1-Iododihydrocodeine • 2-Iododihydrocodeine • 1-Iododihydromorphine • 2-Iododihydromorphine • 1-Iodomorphine • 2-Iodomorphine • Chlorethylmorphine Others Pholcodine Active Opiate Metabolites Codeine-N-Oxide (Genocodeine) • Dihydromorphine-6-glucuronide • Hydromorphone-N-Oxide • Heroin-7,8-Oxide • Morphine-6-glucuronide • 6-Acetylmorphine • Morphine-N-Oxide (Genomorphine) • Naltrexol • Norcodeine • Normorphine Morphinans Morphinan Series 4-chlorophenylpyridomorphinan • Cyclorphan • Dextrallorphan • Dimemorfan • Levargorphan • Levorphanol • Levorphan • Levophenacylmorphan • Levomethorphan • Norlevorphanol • N-Methylmorphinan • Oxilorphan • Phenomorphan • Methorphan / Racemethorphan • Morphanol / Racemorphanol • Ro4-1539 • Stephodeline • Xorphanol Others 1-Nitroaknadinine • 14-episinomenine • 5,6-Dihydronorsalutaridine • 6-Ketonalbuphine • Aknadinine • Butorphanol • Cephakicine • Cephasamine • Cyprodime • Drotebanol • Fenfangjine G • Nalbuphine • Sinococuline • Sinomenine (Cocculine) • Tannagine Benzomorphans 5,9-DEHB • Alazocine • Anazocine • Bremazocine • Cogazocine • Dezocine • Eptazocine • Etazocine • Ethylketocyclazocine • Fluorophen • Ketazocine • Metazocine • Pentazocine • Phenazocine • Quadazocine • Thiazocine • Tonazocine • Volazocine • Zenazocine 4-Phenylpiperidines Pethidines (Meperidines) 4-Fluoromeperidine • Allylnorpethidine • Anileridine • Benzethidine • Carperidine • Difenoxin • Diphenoxylate • Etoxeridine (Carbetidine) • Furethidine • Hydroxypethidine (Bemidone) • Hydroxymethoxypethidine • Morpheridine • Oxpheneridine (Carbamethidine) • Meperidine-N-Oxide • Pethidine (Meperidine) • Pethidine Intermediate A • Pethidine Intermediate B (Norpethidine) • Pethidine Intermediate C (Pethidinic Acid) • Pheneridine • Phenoperidine • Piminodine • Properidine (Ipropethidine) • Sameridine Prodines Allylprodine • Isopromedol • Meprodine (α-meprodine / β-meprodine) • MPPP (Desmethylprodine) • PEPAP • Prodine (α-prodine / β-prodine) • Prosidol • Trimeperidine (Promedol) Ketobemidones Acetoxyketobemidone • Droxypropine • Ketobemidone • Methylketobemidone • Propylketobemidone Others Alvimopan • Loperamide • Picenadol Open Chain Opioids Amidones Dextromethadone • Dextroisomethadone • Dipipanone • Hexalgon (Norpipanone) • Isomethadone • Levoisomethadone • Levomethadone • Methadone • Methadone intermediate • Normethadone • Norpipanone • Phenadoxone (Heptazone) • Pipidone Methadols Dimepheptanol (Racemethadol) • Levacetylmethadol • Noracetylmethadol Moramides Dextromoramide • Levomoramide • Moramide intermediate • Racemoramide Thiambutenes Diallylthiambutene • Diethylthiambutene • Dimethylthiambutene • Ethylmethylthiambutene • Methylisopropylthiambutene • Methylpropylthiambutene • Morpholinylthiambutene • Piperidylthiambutene • Pyrrolidinylthiambutene • Thiambutene • Tipepidine Phenalkoxams Dextropropoxyphene (Propoxyphene) • Dimenoxadol • Dioxaphetyl Butyrate • Levopropoxyphene • Norpropoxyphene Ampromides Diampromide • Phenampromide • Propiram Others IC-26 • Isoaminile • Lefetamine • R-4066 Anilidopiperidines 3-Allylfentanyl • 3-Methylfentanyl • 3-Methylthiofentanyl • 4-Phenylfentanyl • Alfentanil • α-methylacetylfentanyl • α-methylfentanyl • α-methylthiofentanyl • Benzylfentanyl • β-hydroxyfentanyl • β-hydroxythiofentanyl • β-methylfentanyl • Brifentanil • Carfentanil • Fentanyl • Lofentanil • Mirfentanil • Ocfentanil • Ohmefentanyl • Parafluorofentanyl • Phenaridine • Remifentanil • Sufentanil • Thenylfentanyl • Thiofentanyl • Trefentanil Oripavine derivatives 6,14-Endoethenotetrahydrooripavine • 7-PET • Acetorphine • Alletorphine • BU-48 • Buprenorphine • Butorphine • Cyprenorphine • Dihydroetorphine • Etorphine • 18,19-Dehydrobuprenorphine (HS-599) • N-cyclopropylmethyl-noretorphine • Nepenthone • Norbuprenorphine • N-phenethyletorphine • Thevinone • Thienorphine Phenazepanes Ethoheptazine • Meptazinol • Metheptazine • Metethoheptazine • Proheptazine Pirinitramides Bezitramide • Piritramide Benzimidazoles Clonitazene • Etonitazene • Nitazene Indoles 18-MC • 7-Acetoxymitragynine • 7-Hydroxymitragynine • Akuammidine • Akuammine • Eseroline • Hodgkinsine • Mitragynine • Pericine • ψ-Akuammigine Diphenylmethylpiperazines BW373U86 • DPI-221 • DPI-287 • DPI-3290 • SNC-80 Opioid peptides see also: Opioid Neuropeptides Adrenorphin • Amidorphin • Casomorphin • DADLE • DALDA • DAMGO • Dermenkephalin • Dermorphin • Deltorphin • DPDPE • Dynorphin • Endomorphin • Endorphins • Enkephalin • Gliadorphin • Morphiceptin • Nociceptin • Octreotide • Opiorphin • Rubiscolin • TRIMU 5 Others 3-(3-Methoxyphenyl)-3-ethoxycarbonyltropane • AH-7921 • Azaprocin • BDPC • Bisnortilidine • BRL-52537 • Bromadoline • C-8813 • Ciramadol • Doxpicomine • Enadoline • Faxeladol • GR-89696 • Herkinorin • ICI-199,441 • ICI-204,448 • J-113,397 • JTC-801 • Ketamine • LPK-26 • Methopholine • N-Desmethylclozapine • NNC 63-0532 • Nortilidine • O-Desmethyltramadol • Phenadone • Phencyclidine • Prodilidine • Profadol • Ro64-6198 • Salvinorin A • SB-612,111 • SC-17599 • RWJ-394,674 • TAN-67 • Tapentadol • Tecodine • Tifluadom • Tilidine • Tramadol • Trimebutine • U-50,488 • U-69,593 • Viminol • W-18 • Opioid Antagonists & Inverse-Agonists 5'-Guanidinonaltrindole • β-Funaltrexamine • 6β-Naltrexol • Alvimopan • Binaltorphimine • Chlornaltrexamine • Clocinnamox • Cyclazocine • Cyprodime • Diprenorphine (M5050) • Fedotozine • JDTic • Levallorphan • Methocinnamox • Methylnaltrexone • Nalfurafine • Nalmefene • Nalmexone • Naloxazone • Naloxonazine • Naloxone • Naloxone benzoylhydrazone • Nalorphine • Naltrexone • Naltriben • Naltrindole • Norbinaltorphimine • Oxilorphan • S-allyl-3-hydroxy-17-thioniamorphinan (SAHTM)

This biochemistry article is a stub. You can help Wikipedia by expanding it.v · d · e