title: 5-OMe-UDP is a potent and selective P2Y(6)-receptor agonist.
abstract: P2Y nucleotide receptors (P2Y-Rs) play important physiological roles. However, most of the P2Y-R subtypes are still lacking potent and selective agonists and antagonists. Based on data mining analysis of binding interactions in 44 protein-uridine nucleos(t)ides complexes, we designed uracil nucleotides, substituted at the C5/C6 position. All C6-substituted derivatives were inactive at the P2Y(2,4,6)-Rs, while out of the C5-substituted analogues, only 5-OMe-UD(T)P showed activity. To rationalize the data, the ionization and conformation of these analogues were evaluated. The pK(a) values of most analogues substituted at the C5/C6 positions were unaltered compared to UTP (pK(a) 9.42), except for 5-F-UTP nucleotide (pK(a) 7.85). C6-substituted analogues adopt the syn or high-syn conformations, which are disfavored by the receptors, while 5-OMe-UD(T)P adopt the favored anti conformation. Furthermore, 5-OMe-UDP adopts the S sugar puckering, which is the conformation preferred by the P2Y(6)-R, but not the P2Y(2)- or P2Y(4)-Rs. 5-OMe-UDP fulfills the conformational and H-bonding requirements of P2Y(6)-R, thus, making a potent P2Y(6)-R agonist (EC(50) 0.08 microM), more than UDP (EC(50) 0.14 microM).
authors.affiliation: Department of Chemistry, Gonda-Goldschmied Medical Research Center, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Tamar
authors.initials: T
authors.lastname: Ginsburg-Shmuel
authors.forename: Michael
authors.initials: M
authors.lastname: Haas
authors.forename: Marlen
authors.initials: M
authors.lastname: Schumann
authors.forename: Georg
authors.initials: G
authors.lastname: Reiser
authors.forename: Ori
authors.initials: O
authors.lastname: Kalid
authors.forename: Noa
authors.initials: N
authors.lastname: Stern
authors.forename: Bilha
authors.initials: B
authors.lastname: Fischer
mesh_terms: D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D006801:Humans; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2 / Q000235:genetics; D013329:Structure-Activity Relationship; D014162:Transfection; D014530:Uridine Diphosphate / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology
chemical_list: D008024:Ligands; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; C099845:purinoceptor P2Y6; D014530:Uridine Diphosphate; D002118:Calcium