title: [Isolation and properties of phosphoribosyl-aminoimidazole-succinocarboxyamide-synthestase from Saccharomyces cerevisiae yeasts].
abstract: An isolation procedure for phosphoribosyl succinocarboxamideaminoimidazole synthetase (SAICAR synthetase) (EC 6.3.2.6) has been developed. Pure SAICAR synthetase was found to be a monomeric protein with the apparent molecular weight of 36 kDa. The Michaelis constant for the three substrates of the reaction are 1.6 microM for CAIR, 14 microM for ATP and 960 microM for aspartic acid. The structural analogs of CAIR, 5-aminoimidazole ribotide and 5-aminoimidazole-4-carboxamide ribotide, act as competitive inhibitors of SAICAR synthetase. GTP and 2'-dATP can substitute for ATP in the reaction, while CTP and UTP inhibit the enzyme. No structural analogs of the aspartic acid were found to have affinity for SAICAR synthetase. The optimal reaction conditions for the enzyme were established to be at pH 8.0 and magnesium chloride concentration around 5 mM.
authors.forename: K V
authors.initials: KV
authors.lastname: Ostanin
authors.forename: V V
authors.initials: VV
authors.lastname: Alenin
authors.forename: V D
authors.initials: VD
authors.lastname: Domkin
authors.forename: M N
authors.initials: MN
authors.lastname: Smirnov
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D001667:Binding, Competitive; D002850:Chromatography, Gel; D003570:Cytidine Triphosphate / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006160:Guanosine Triphosphate / Q000494:pharmacology; D010453:Peptide Synthases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity; D014544:Uridine Triphosphate / Q000494:pharmacology
chemical_list: D003570:Cytidine Triphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D010453:Peptide Synthases; C022379:phosphoribosylaminoimidazole-succinocarboxamide synthetase; D014544:Uridine Triphosphate
vernacular_title: Vydelenie i svoĭstva fosforibozil-aminoimidazol-suktsinokarboksamid- sintetazy drozhzheĭ Saccharmomyces cerevisiae.