title: Deltorphins: a family of naturally occurring peptides with high affinity and selectivity for delta opioid binding sites.
abstract: Deltorphins are endogenous linear heptapeptides, isolated from skin extracts of frogs belonging to the genus Phyllomedusa, that have a higher affinity and selectivity for delta opioid binding sites than any other natural compound known. Two deltorphins with the sequence Tyr-Ala-Phe-Asp(or Glu)-Val-Val-Gly-NH2 have been isolated from skin extracts of Phyllomedusa bicolor. The alanine in position 2 is in the D configuration. These peptides, [D-Ala2]deltorphins I and II, show an even higher affinity for delta receptors than the previously characterized deltorphin, which contains D-methionine as the second amino acid. These peptides show some similarity to another constituent of Phyllomedusa skin, dermorphin, which is highly selective for mu-opioid receptors. These peptides all have the N-terminal sequence Tyr-D-Xaa-Phe, where D-Xaa is either D-alanine or D-methionine. While this structure seems to be capable of activating both mu and delta opioid receptors, differences in the C-terminal regions of these peptides are probably responsible for the observed high receptor selectivity of dermorphin and deltorphin.
authors.affiliation: Department of Biochemical Sciences, University La Sapienza, Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Erspamer
authors.forename: P
authors.initials: P
authors.lastname: Melchiorri
authors.forename: G
authors.initials: G
authors.lastname: Falconieri-Erspamer
authors.forename: L
authors.initials: L
authors.lastname: Negri
authors.forename: R
authors.initials: R
authors.lastname: Corsi
authors.forename: C
authors.initials: C
authors.lastname: Severini
authors.forename: D
authors.initials: D
authors.lastname: Barra
authors.forename: M
authors.initials: M
authors.lastname: Simmaco
authors.forename: G
authors.initials: G
authors.lastname: Kreil
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001001:Anura; D001921:Brain / Q000378:metabolism*; D004745:Enkephalins / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008566:Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D009842:Oligopeptides / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D012867:Skin; D014649:Vas Deferens / Q000187:drug effects / Q000502:physiology
chemical_list: D004745:Enkephalins; D009842:Oligopeptides; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; C060208:deltorphin I, Ala(2)-; C060209:deltorphin II, Ala(2)-