Immunological quantitation of tyrosinase from wild-type and albino mutant mice

The relationship between gene dosage, enzyme activity, and level of immunologically cross-reacting material (CRM) was examined in mammalian tyrosinase (EC 1.14.18.1) by rocket immunoelectrophoresis. Skin extracts from mice heterozygous (C/c) and homozygous (c/c) for the albino locus contain 46% and 0% of CRM, respectively, as compared with wild-type (C/C) animals. Enzyme activity and CRM level were directly proportional in these genotypes, suggesting that the albino locus controls the quantity of tyrosinase produced in melanocytes.