title: [Endomorphins--endogenous ligands of the mu-opioid receptor].
abstract: Two endogenous opioid peptides with extremely high mu-opioid receptor affinity and selectivity, endomorphin-1 and endomorphin-2, were: discovered and isolated from the mammalian brain in 1997. Endomorphins are amidated tetrapeptides, structurally different from so called typical opioids: enkephalins, dynorphins and endorphins. A protein precursor of endomorphins and a gene encoding their sequence remain unknown. Endomorphins are unable to cross the blood-brain barrier because of their low hydrophobicity. In animal models, these peptides turned out to be very potent in relieving neuropathic and inflammatory pain. In comparison with morphine, a prototype opioid receptor ligand, endomorphins produces less undesired side effects. In this article we describe the discovery of endomorphins, their cellular localization and functions in the organism, as well as their structure-activity relationships and biodegradation pathways.
authors.affiliation: Zakład Chemii Biomolekularnej, Uniwersytet Medyczny w Łodzi, Łódź, Poland.
authors.forename: Renata
authors.initials: R
authors.lastname: Perlikowska
authors.forename: Jakub
authors.initials: J
authors.lastname: Fichna
authors.forename: Anna
authors.initials: A
authors.lastname: Janecka
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D023421:Models, Animal; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D010146:Pain / Q000378:metabolism*; D017450:Receptors, Opioid, mu / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; D017450:Receptors, Opioid, mu; C105293:endomorphin 1; C105294:endomorphin 2