Differentiation of tyrosinase and laccase using 4-hexyl-resorcinol, a tyrosinase inhibitor

Crude extracts of Agaricus bisporus and partially purified mushroom tyrosinase contained tyrosinase and laccase activities. 4-Hexylresorcinol (4HR) and salicylhydroxamic acid (SHAM) inhibited tyrosinase, but not laccase when selective substrates for tyrosinase and laccase were used in enzyme assays. Partially purified laccase from Pyricularia oryzae did not exhibit tyrosinase activity, nor was it inhibited by 4HR or SHAM. Both 4HR and SHAM selectively inhibited tyrosinase isoforms separated by native electrophoresis. At low concentrations, 4HR was a selective inhibitor of tyrosinase and could differentiate between tyrosinase and laccase activities.