Mammalian melanogenesis: tyrosinase versus peroxidase involvement, and activation mechanisms

A study of the enzymes functioning in murine melanogenesis was carried out on tissue homogenates of the black mouse. Several major points were resolved: (a) while the enzyme peroxidase is capable of converting tyrosine to melanin in vitro, it is not responsible for observed melanogenesis in the mouse, (b) a proteolytic activation system for tyrosinase, such as that described for amphibian skin, does not seem to function in mammalian tyrosinase activation, and (c) tyrosinase activity in normal murine tissues can be stimulated with a variety of treatments.