Abstract
An alkaline protease (peptidylpeptide hydrolase, EC class 3.4.4.) of Bacillus natty KMD 1126 was purified by ammonium sulfate fractionation, DEAE cellulose chromatography, CM cellulose chromatography, and Sephadex G 100 gel filtration. It had a pH optimum over the range of 8.5-9.5 toward casein substrate. It was not inactivated by chelating agents or sulfhydryl reagents, but completely inactivated by incubation with DFP. From these results and the substrate specificity, this enzyme resembles to alkaline protease of Bacillus natto Ns. However, the two enzyme differ in specific activity and kinetic properties. This enzyme had not cytolytic activity on Ehrlich ascites carcinoma cells. However, when a mixture of surfactin, the protease, and EDTA was incubated with carcinoma cells, synergetic effect on the cytolysis was observed.
