Mammalian tyrosinase; action on substances structurally related to tyrosine.

Tyrosinase prepared from plant, insect, and marine animal sources catalyzes the oxidation of tyrosine, dihydroxyphenylalanine (dopa), and various structurally similar compounds to darkly colored pigments (2). The enzymatic oxidation of many of the analogues of tyrosine and dopa often proceeds at a faster rate than for tyrosine and dopa themselves (2, 3). The investigation reported here was carried out in order to determine the action of tyrosinase from mammalian sources on various compounds structurally related to tyrosine and dopa so that information regarding the mechanism of mammalian tyrosinase action might be obtained. The possibility of finding competitive inhibitors for mammalian tyrosinase action was also anticipated.