Leu-enkephalin

{{short description|Neurotransmitter}}

{{Chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 442009113

| ImageFile= Leu-enkephalin Structure.svg

| ImageClass = skin-invert-image

| ImageSize=300px

| IUPACName=(2R)-2-[[(2R)-2-[[2-[[2-[[(2R)-2-amino-3-(4-hydroxyphenyl)propanoyl]amino]acetyl]amino]acetyl]amino]-3-phenylpropanoyl]amino]-4-methylpentanoic acid

| OtherNames= [Leu]enkephalin; [Leu⁵]enkephalin;

|Section1={{Chembox Identifiers

| PubChem = 461776

| ChEBI = 89656

| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

| ChemSpiderID = 406229

| SMILES = O=C(O)[C@@H](NC(=O)[C@@H](NC(=O)CNC(=O)CNC(=O)[C@@H](N)Cc1ccc(O)cc1)Cc2ccccc2)CC(C)C

| InChI = 1/C28H37N5O7/c1-17(2)12-23(28(39)40)33-27(38)22(14-18-6-4-3-5-7-18)32-25(36)16-30-24(35)15-31-26(37)21(29)13-19-8-10-20(34)11-9-19/h3-11,17,21-23,34H,12-16,29H2,1-2H3,(H,30,35)(H,31,37)(H,32,36)(H,33,38)(H,39,40)/t21-,22-,23-/m0/s1

| InChIKey = URLZCHNOLZSCCA-VABKMULXBR

| StdInChI_Ref = {{stdinchicite|changed|chemspider}}

| StdInChI = 1S/C28H37N5O7/c1-17(2)12-23(28(39)40)33-27(38)22(14-18-6-4-3-5-7-18)32-25(36)16-30-24(35)15-31-26(37)21(29)13-19-8-10-20(34)11-9-19/h3-11,17,21-23,34H,12-16,29H2,1-2H3,(H,30,35)(H,31,37)(H,32,36)(H,33,38)(H,39,40)/t21-,22-,23-/m0/s1

| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

| StdInChIKey = URLZCHNOLZSCCA-VABKMULXSA-N

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo=58822-25-6

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = RI01R707R6

| ChEMBL_Ref = {{ebicite|changed|EBI}}

| ChEMBL = 8234

| IUPHAR_ligand = 1613

}}

|Section2={{Chembox Properties

| Formula= C₂₈H₃₇N₅O₇

| MolarMass=555.62 g/mol{{cite journal | vauthors = Colaianni L, Kung SC, Taggart DK, Picca RA, Greaves J, Penner RM, Cioffi N | title = Reduction of spectral interferences using ultraclean gold nanowire arrays in the LDI-MS analysis of a model peptide | journal = Analytical and Bioanalytical Chemistry | volume = 406 | issue = 19 | pages = 4571–83 | date = July 2014 | pmid = 24980599 | doi = 10.1007/s00216-014-7876-7 | s2cid = 24046957 }}

| MeltingPt=

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| Solubility=

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|Section3={{Chembox Hazards

| MainHazards=

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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.{{cite journal | vauthors = Lazarus LH, Ling N, Guillemin R | title = beta-Lipotropin as a prohormone for the morphinomimetic peptides endorphins and enkephalins | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 73 | issue = 6 | pages = 2156–9 | date = June 1976 | pmid = 1064883 | pmc = 430469 | doi = 10.1073/pnas.73.6.2156| bibcode = 1976PNAS...73.2156L | doi-access = free }}{{cite journal | vauthors = Hughes J, Kosterlitz HW, Smith TW | title = The distribution of methionine-enkephalin and leucine-enkephalin in the brain and peripheral tissues. 1977 | journal = British Journal of Pharmacology | volume = 120 | issue = 4 Suppl | pages = 428–36; discussion 426–7 | date = February 1997 | pmid = 9142421 | pmc = 3224324 | doi = 10.1111/j.1476-5381.1997.tb06829.x}} 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.{{cite journal | vauthors = Schiller PW, Yam CF, Lis M | title = Evidence for topographical analogy between methionine-enkephalin and morphine derivatives | journal = Biochemistry | volume = 16 | issue = 9 | pages = 1831–8 | date = May 1977 | pmid = 870028 | doi=10.1021/bi00628a011}} Leu-enkephalin has agonistic actions at both the μ- and δ-opioid receptors, with significantly greater preference for the latter. It has little to no effect on the κ-opioid receptor.{{cite journal | vauthors = Porreca F, Mosberg HI, Hurst R, Hruby VJ, Burks TF | title = Roles of mu, delta and kappa opioid receptors in spinal and supraspinal mediation of gastrointestinal transit effects and hot-plate analgesia in the mouse | journal = The Journal of Pharmacology and Experimental Therapeutics | volume = 230 | issue = 2 | pages = 341–8 | date = August 1984 | pmid = 6086883 }}{{cite journal | vauthors = Raynor K, Kong H, Chen Y, Yasuda K, Yu L, Bell GI, Reisine T | title = Pharmacological characterization of the cloned kappa-, delta-, and mu-opioid receptors | journal = Molecular Pharmacology | volume = 45 | issue = 2 | pages = 330–4 | date = February 1994 | pmid = 8114680 }}

A nasal spray formulation of leu-enkephalin (developmental code names NES-100, NM-0127, NM-127, PES-200; proposed brand name Envelta) is under development by Virpax Pharmaceuticals for the treatment of pain and post-traumatic stress disorder (PTSD).{{cite web | title=Leucine enkephalin - Virpax Pharmaceuticals | website=AdisInsight | date=20 November 2023 | url=https://adisinsight.springer.com/drugs/800046784 | access-date=22 October 2024}} As of November 2023, it is up to the preclinical stage of development for these indications.