title: Tryptophan replacement in the nociceptin/orphanin FQ receptor ligand Ac-RYYRWK-NH2.
abstract: In the present study we describe the in vitro pharmacological characterization of the nociceptin/orphanin FQ (N/OFQ) receptor (NOP) ligand Ac-RYYRWK-NH2 and the synthesis and biological evaluation of 13 Trp5 substituted Ac-RYYRWK-NH2 analogs. Results indicate that Ac-RYYRWK-NH2 behaves as a highly potent and selective partial agonist at the NOP receptors and that the whole indole moiety of the Trp5 side chain is not required, being a phenyl-ethyl side chain already sufficient for maintaining high potency.
authors.affiliation: Section of Pharmacology and Neuroscience Centre, Department of Experimental and Clinical Medicine, University of Ferrara, 44100 Ferrara, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Carra'
authors.forename: G
authors.initials: G
authors.lastname: Calo'
authors.forename: B
authors.initials: B
authors.lastname: Spagnolo
authors.forename: R
authors.initials: R
authors.lastname: Guerrini
authors.forename: M
authors.initials: M
authors.lastname: Arduin
authors.forename: E
authors.initials: E
authors.lastname: Marzola
authors.forename: C
authors.initials: C
authors.lastname: Trapella
authors.forename: D
authors.initials: D
authors.lastname: Regoli
authors.forename: S
authors.initials: S
authors.lastname: Salvadori
mesh_terms: D000595:Amino Acid Sequence; D024322:Amino Acids, Aromatic / Q000737:chemistry*; D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009842:Oligopeptides / Q000737:chemistry* / Q000494:pharmacology; D018847:Opioid Peptides / Q000819:agonists / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014364:Tryptophan / Q000737:chemistry*; D014649:Vas Deferens / Q000187:drug effects / Q000502:physiology; D000097629:Nociceptin
chemical_list: D024322:Amino Acids, Aromatic; D009842:Oligopeptides; D018847:Opioid Peptides; D014364:Tryptophan; D000097629:Nociceptin; C479838:(Nphe(1),Arg(14),Lys(15))N-OFQ NH(2); C404152:CAM 6369