A Novel Acid Protease from Haploid Amoebae of Physarum polycephalum, and its Changes during Mating and Subsequent Differentiation into Diploid Plasmodia

Abstract

Haploid myxamoebae of the true slime mold, Physarum poly-cephalum contained an acid protease that had a highly acidic pH optimum of 1.4. This enzyme was not considered to have-SH groups, DAN-Cu²⁺ reactive-carboxyl groups, or an aspartic acid moiety in its active center. Its activity appeared to decrease with time during mating and the subsequent differ-entiation into the diploid, multinuclear plasmodia.