CHARACTERIZATION OF MICROSOMAL ANILINE HYDROXYLASE OF RAINBOW-TROUT, SALMO-GAIRDNERI

Aniline hydroxylase from liver microsomes of rainbow trout Salmo gaird neri converted aniline to p-aminophenol, the specific activity being 0 .068 nmoles/min/mg protein in potassium phosphate buffer, pH 7.4 at 25 degrees C. The maximal rate of the enzyme reaction was found at anili ne concentrations above 5 mM and in the presence of NADPH. V-max and K -m were 0.048 nmoles/min/mg and 0.105 mM respectively. The Hill plot s howed the Hill constant to be 1.02 indicating one substrate binding si te with no cooperativity. Ca2+ and Mg2+ at concentrations ranging betw een 1-10 mM stimulated the enzyme activity.