Oxygen consumption during the indole-03-acetic acid oxidation catalyzed by peroxidase.Effect of the enzyme/substrate ratio

Abstract

Oxygen consumption during the oxidation of indole-03-acetic acid (IAA) by peroxidase has been studied, in conditions of no limitation by oxygen.For different enzyme/substrate ratios the quotient O2 consumed/IAA oxidized shows rather small differences and it is always less than unity.During the reaction, however, the quotient undergoes important variations because oxygen uptake ceases long before the decarboxylation of IAA.The results are discussed in the light of previous proposed mechanisms.