title: Spectroscopic and kinetic studies of interactions of calf spleen purine nucleoside phosphorylase with 8-azaguanine, and its 9-(2-phosphonylmethoxyethyl) derivative.
abstract: Spectroscopic and kinetic studies of interactions of calf spleen purine nucleoside phosphorylase with 8-azaguanine, an excellent fluorescent/fluorogenic substrate for the synthetic pathway of the reaction, and its 9-(2-phosphonylmethoxyethyl) derivative, a bisubstrate analogue inhibitor, were carried out. The goal was to clarify the catalytic mechanism of the enzymatic reaction by identification of ionic/tautomeric forms of these ligands in the complex with PNP.
authors.affiliation: Department of Biophysics, University of Warmia and Mazury, 4 Oczapowskiego St., Olsztyn 10-719, Poland. jacek.wie@uwm.edu.pl
authors.forename: Jacek
authors.initials: J
authors.lastname: Wierzchowski
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Stepniak
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Bzowska
authors.forename: David
authors.initials: D
authors.lastname: Shugar
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D001375:Azaguanine / Q000737:chemistry* / Q000494:pharmacology; D002417:Cattle; D004347:Drug Interactions; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008024:Ligands; D046911:Macromolecular Substances / Q000737:chemistry; D008956:Models, Chemical; D011683:Purine-Nucleoside Phosphorylase / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013154:Spleen / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D000964:Antimetabolites, Antineoplastic; D008024:Ligands; D046911:Macromolecular Substances; D011683:Purine-Nucleoside Phosphorylase; D001375:Azaguanine