Characterization of a Neutral Protease Gene of Bacillus subtilis Isolated from the Guts of Bombyx mori

-1 . Meanwhile, a gene encoding a kind of neutral protease was cloned and its prokaryotic expression in Escherichia coli was also carried out. The cDNA of this gene was 2644bp encoding a protein with a molecular weight of about 60 kD, which was confirmed by SDS-PAGE. The positive transformant strains were cultured with different concentrations of IPTG and their enzymatic activities of expressed proteins was determined by Folin-phenol method, which demonstrated that the constructed expression system had an efficient expression capacity for the neutral protease NPR. These results provided a foundation for further function study of this neutral protease.