Purification and Properties of Pepsidine Hydrolase

Abstract

Pepsidine hydrolase, which was produced by Bacillus pumilus EF49-210 and catalyzed the two-step hydrolysis of pepsidines, was purified by means of ammonium sulfate precipitation, DEAE-Sephadex column chromatography and Sephadex G-200 and Sepharose 6 B gel filtrations. The purified enzyme was homogeneous in disc electrophoresis and the ratio of the deacylating activity to the valine-splitting activity remained almost unchanged throughout the purification processes, showing that both activities were inherent in the enzyme.
The substrate specificity of the purified enzyme showed the enzyme to be a kind of aminopeptidase. The molecular weight of the enzyme was calculated to be 320, 000. The enzyme consisted of two identical subunits and showed the maximum activities at pH 7.5 on both activities.