title: [Peroxidase activity of catalase modified by progesterone].
abstract: Catalase conjugates with 3, 7, 9 and 42 progesterone molecules were obtained by the reaction between the enzyme and N-oxy-succinimide ether of 3-0-carboxymethyloxime of progesterone. The enzyme modified by 42 progesterone molecules is effective in o-dianisidine oxidation by hydrogen peroxide and has a kcat/KM value of 512 M-1 s-1. The catalase conjugates with 3, 7 and 9 progesterone molecules exhibit a high activity during o-dianisidine oxidation by cumene hydroperoxide. The activity of conjugates is higher than that of the native non-modified enzyme in the same reaction. The maximum effectiveness was observed for catalase modified by 7 progesterone molecules. This conjugate is characterized by kcat/KM of 99,000 M-1 s-1 at 30 degrees C. The effect of the degree of enzyme modification on the kinetic parameters of o-dianisidine oxidation by H2O2 and cumene hydroperoxide is discussed.
mesh_terms: D000818:Animals; D001555:Benzene Derivatives / Q000378:metabolism; D002374:Catalase / Q000378:metabolism*; D002417:Cattle; D003962:Dianisidine / Q000378:metabolism; D066298:In Vitro Techniques; D007527:Isoenzymes; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D010084:Oxidation-Reduction; D009195:Peroxidase; D010544:Peroxidases; D011374:Progesterone / Q000494:pharmacology*
chemical_list: D001555:Benzene Derivatives; D007527:Isoenzymes; D011374:Progesterone; D010544:Peroxidases; D002374:Catalase; D009195:Peroxidase; D003962:Dianisidine; C007164:cumene hydroperoxide
vernacular_title: Peroksidaznaia aktivnost' katalazy, modifitsirovannoĭ progesteronom.