title: [Substrate specificity, inhibitors and kinetics of deamidase AG (asparaginase-glutaminase) from Pseudomonas fluorescens AG].
abstract: Deamidase AG (asparaginase-glutaminase) from Pseudomonas fluorescens AG was shown to hydrolyze 1-glutamine and 1-asparagine highly effectively. Besides, the enzyme exhibited the rather high rate of deamidation of D-asparagine and D-glutamine (70% and 100%, respectively), Nalpha-butyl asparagine (63%) and among peptides -- of glycyl-L-asparagine (40%). L-glutamic acid gamma-methyl ester was hydrolyzed only slightly (5%). Effect of several substrate analogues on the deamidase AG activity was studied as well. Albiciine (alpha-amino-beta-ureide propionic acid) proved to be the strongest inhibitor (100%). Beta-Methyl aspartic acid, S-carbamoyl cysteine, alpha-ketoglutaric acid showed the slight inhibitory effect (20%). Amount of active centres per enzyme molecule was estimated by means of 14C-albiciine. Deamidase AG had apparently only one active centre. In estimation of relationship between the rate of reaction and substrate (L-asparagine) concentration, the reaction was found to follow Michaelis-Menten kinetics, K(m) = 4.5 with 10-4 M.
mesh_terms: D001215:Asparaginase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001665:Binding Sites / Q000187:drug effects; D003641:Deamination; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D005972:Glutaminase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D011551:Pseudomonas fluorescens / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D001215:Asparaginase; D005972:Glutaminase
vernacular_title: Nekotorye dannye o substratnoĭ spetsifichnosti, ingibitorakh i kinetike dezamidazy AG (asparaginazy-glutaminazy) iz Pseudomonas fluorescens AG.