title: New features of the delta opioid receptor: conformational properties of deltorphin I analogues.
abstract: Deltorphin I is an opioid peptide of sequence H-Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2, recently isolated from the skin of Phyllomedusa bicolor. Its enormous selectivity towards the delta opioid receptor and the similarity of the conformation of the N-terminal part of the sequence with that of dermorphin (H-Tyr-D-Ala-he-Gly-Tyr-Pro-Ser-NH2), a mu selective peptide, prompted the synthesis, biological evaluation and comparative conformational study of four analogs. A 1H-NMR study showed that the conformational preferences of the N-terminal sequences of all peptides are similar. The different selectivities towards opioid receptors have been interpreted in terms of charge effects in the interaction with the membrane and at the receptor site and of hydrophobicity of the C-terminal part, when structured in a folded conformation.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, University of Ferrara, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Balboni
authors.forename: M
authors.initials: M
authors.lastname: Marastoni
authors.forename: D
authors.initials: D
authors.lastname: Picone
authors.forename: S
authors.initials: S
authors.lastname: Salvadori
authors.forename: T
authors.initials: T
authors.lastname: Tancredi
authors.forename: P A
authors.initials: PA
authors.lastname: Temussi
authors.forename: R
authors.initials: R
authors.lastname: Tomatis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D011487:Protein Conformation; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; C059567:deltorphin