title: Lead optimization of P5U and urantide: discovery of novel potent ligands at the urotensin-II receptor.
abstract: We have optimized 1 (P5U) and urantide, two important ligands at the h-UT receptor, designing several analogues by the exchange of the Tyr9 residue with different unnatural aromatic amino acids. This study allowed us to discover novel ligands with improved activity. In particular, the replacement of the Tyr9 residue by (pCN)Phe or (pNO2)Phe within the urantide sequence led to compounds 13 (UPG-83) and 15 (UPG-95), respectively, which showed pure antagonist activity toward UT receptor in a rat aorta bioassay. More interestingly, the replacement of the Tyr9 in 1 sequence with the Btz or the (3,4-Cl)Phe residues led to superagonists 6 (UPG-100) and 10 (UPG-92) with pEC50 values at least 1.4 log higher than that of 1, being the most potent UT agonists discovered to date. Compounds 10 and 13 showed also a good stability in a serum proteolytic assay. These ligands represent new useful tools to further characterize the urotensinergic system in human physiopathology.
authors.affiliation: Department of Pharmacy, University of Naples "Federico II" , I-80131 Naples, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Carotenuto
authors.forename: Luigia
authors.initials: L
authors.lastname: Auriemma
authors.forename: Francesco
authors.initials: F
authors.lastname: Merlino
authors.forename: Ali Munaim
authors.initials: AM
authors.lastname: Yousif
authors.forename: Daniela
authors.initials: D
authors.lastname: Marasco
authors.forename: Antonio
authors.initials: A
authors.lastname: Limatola
authors.forename: Pietro
authors.initials: P
authors.lastname: Campiglia
authors.forename: Isabel
authors.initials: I
authors.lastname: Gomez-Monterrey
authors.forename: Paolo
authors.initials: P
authors.lastname: Santicioli
authors.forename: Stefania
authors.initials: S
authors.lastname: Meini
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Maggi
authors.forename: Ettore
authors.initials: E
authors.lastname: Novellino
authors.forename: Paolo
authors.initials: P
authors.lastname: Grieco
mesh_terms: D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014579:Urotensins / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D008024:Ligands; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D043562:Receptors, G-Protein-Coupled; C121697:UTS2R protein, human; D014579:Urotensins; C466635:aspartyl-cyclo(penicillamyl-phenylalanyl-tryptophyl-lysyl-tyrosyl-cysteinyl)valine; C492079:urotensin II (4-11), Pen(5)-Trp(7)-Orn(8)-