Studies on Phyto-peroxidase

Part XVI. Aerobic Destruction of Indole-3-acetic Acid Catalyzed by Crystalline Japanese-radish Peroxidase a and c

Abstract

Both crystalline Japanese-radish peroxidase a and c could catalyze the aerobic destruction of indole-3-acetic acid in the presence of a small amount of hydrogen peroxide as an inducer. The pH dependences of the enzymic activities of peroxidase a and c were different from each other. The optimum pH of peroxidase a was found at 3.6, while that of peroxidase c lied in a broad range over 3 to 4.8.In lower concentrations of both peroxidases at pH 3.8 and 6.0, the major product of the reaction was identical with that presented by Ray with using an Omphalia enzyme, which would probably be methyldioxindole, while, in higher concentrations of both peroxidases at pH 3.8, the major product was found to be indolealdehyde.