Secretion of Tyrosinase in Streptomyces glaucescens

Abstract

In Streptomyces glaucescens, the intracellular and the extracellular enzyme forms of tyrosinase were found to be indentical in molecular weight (29 000), in copper content (0.21%), in the 19 amino acids at the amino-terminal end and in the ratio of cresolase to catecholase activity (0,005). The tyrosinase secretion process exhibited a constant rate of 0.15 units h-1 (mg protein)-1. Under highly induced conditions intracellular tyrosinase was accumulated. Mutations responsible for the non-melanogenic, tyrosinase-positive non-secretor mutant type are located chromosomally on the upper right arc of the S. glaucescens map near the ade-1 marker.