Tyrosinase
Tyrosinases (EC 1.14.18.1) catalyze the oxidations of both monophenols (cresolase or monophenolase activity) and o-diphenols (catecholase or diphenolase activity) into reactive o-quinones. Tyrosinase is a multifunctional, glycosylated, and copper-containing oxidase, and it is the key protein involved in mammalian melanogenesis and is responsible for enzymatic browning reactions in damaged fruits during post-harvest handling and processing[1]. In view of its role in pigmentation, tyrosinase inhibitors have become increasingly important in the cosmetic and medicinal products used in the prevention of hyperpigmentaion (due to UV radiation)[2].
[1] T.S. Chang. An updated review of tyrosinase inhibitors. Int J Mol Sci. 2009 May 26;10(6):2440-75.
[2] M.T.H. Khan. Molecular design of tyrosinase inhibitors: A critical review of promising novel inhibitors from synthetic origins. Pure Appl. Chem., 2007, 79, 12, 2277-2295.