Inhibitory effects on mushroom tyrosinase by p-alkoxybenzoic acids

The inhibitory kinetics of the diphenolase of mushroom tyrosinase by seven p-alkoxybenzoic acids has been studied. The results show that these derivatives of benzoic acid behave as reversible inhibitors. Among them, p-hydroxybenzoic acid is competitive, while p-methoxybenzoic acid is non-competitive, p-ethoxybenzoic acid is mixed-II type, and the rest all behave as classical uncompetitive inhibitors. The inhibition constants of all of the seven compounds assayed, characterizing the inhibition, were evaluated. The models of the interactions between the enzyme and the inhibitors are compared.