Studies on the Mechanism of Mold Protease Production

Abstract

Inactive protease in the cell free extracts obtained from growing cells of Aspergillus sojae KS was collected in a supernatant of ultracentrifugation at 14×l0⁴ g, and in fractions obtained by acetone of 35~50 per cent and by ammonium sulfate of 0.5~0.6 saturation.

The inactive protease has the same resistance against pH or heat treatments as active protease has. The activation of the inactive protease was maximal between pH 5~6, and was accelerated by several kinds of protease, and was not affected by thioglycollate and KCN.