[Ortho-dianizidine micromethod of determining L-phenylalanine-alpha-oxidase activity]

A micromethod is developed for estimation of 1-phenylalanine-alpha-oxidase activity from Trichoderma sp. The method is based on interaction of H2O2 formed in the reaction with o-dianisidine.HCl. Optimal conditions were adopted for estimation of the new enzyme activity from Trichoderma sp. The enzyme had Km = 2.5.10(-3) M and Vmax = 0.42 U/mg at 20 mM concentration of phenylalanine in the incubation mixture; the highest enzymatic activity was estimated in citrate buffer, pH 5.0. The method is simple, precise and reproducible.