Inhibition of the tyrosinase oxidation of one substrate by another.
The catalytic oxidation of catechol by crude preparations of mushroom tyrosinase was studied by a method yielding data on initial reaction velocities. Graphical analysis of the results suggests that an excess of catechol inhibits its own oxidation by a competitive process, thus accounting for the observed optimum in the substrate concentration. However, added phenol, though itself a substrate, inhibits the enzymatic oxidation of catechol by a process that is neither competitive nor non-competitive, but a mixture of the two types. Mechanisms of this inhibition of the enzyme by a second substrate are discussed in exploring the problem of substrate-substrate inhibition.
D002396:Catechols; D014442:Monophenol Monooxygenase; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000037:antagonists & inhibitors*; D010636:Phenols / Q000494:pharmacology*
D002396:Catechols; D010636:Phenols; D010088:Oxidoreductases; D014442:Monophenol Monooxygenase; C034221:catechol
OXIDASES/antagonists; PHENOLS/pharmacology