[Effects of nucleophils on kinetic parameters of peroxidase-catalyzed oxidative reactions].

The effect of imidazole on the kinetic parameters of reactions of potassium ferrocyanide and o-dianizidine peroxidation by hydrogen peroxide within a wide range of pH was studied. It was shown that imidazole activates the reaction of o-dianizidine peroxidation at pH greater than or equal to 6.5, but does not affect the oxidation of potassium ferrocyanide. It was also found that imidazole causes a similar increase in the kkat and Km, i. e. non-competitive activation occurs. The data obtained suggest a possible mechanism of the activator effect. Differences in the mechanism of interaction of various substrates uith peroxidase are discussed.