Expression, purification, and characterization of a thermophilic neutral protease from Bacillus stearothermophilus in Bacillus subtilis  

作　　者：ZHANG Min1,2, ZHAO Cong2, DU LianXiang2, LU FuPing2 & GAO Chen3 1 College of Engineering, Shenyang Agricultural University, Shenyang 110161, China 2 College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China 3 College of Life Science, Nankai University, Tianjin 300071, China 

出　　处：《Science China(Life Sciences)》2008年第1期52-59,共8页中国科学（生命科学英文版）

基　　金：Supported by the "863" High-Tech Research Project of China (Grant No. 2007AA 02Z212)

摘　　要：The gene coding for a thermophilic neutral protease from Bacillus stearothermophilus was expressed in Bacillus subtilis DB104, under the control of the sacB gene promoter. This was followed by either the native signal peptide sequence of this protease or the signal peptide sequence of the sacB gene. The protease was purified 3.8-fold, with a specific activity of 16530 U mg-1. As analyzed by SDS-PAGE, the molecular mass of the expressed protease was about 35 kDa, and the optimal temperature and pH of the protease were 65℃ and 7.5, respectively. Moreover, it still had about 80% activity after 1 h reaction at 65 ℃ .The gene coding for a thermophilic neutral protease from Bacillus stearothermophilus was expressed in Bacillus subtilis DB104, under the control of the sacB gene promoter. This was followed by either the native signal peptide sequence of this protease or the signal peptide sequence of the sacB gene. The protease was purified 3.8-fold, with a specific activity of 16530 U mg-1. As analyzed by SDS-PAGE, the molecular mass of the expressed protease was about 35 kDa, and the optimal temperature and pH of the protease were 65℃ and 7.5, respectively. Moreover, it still had about 80% activity after 1 h reaction at 65 ℃ .

关 键 词：Bacillus SUBTILIS THERMOPHILIC neutral PROTEASE EXPRESSION PURIFICATION CHARACTERIZATION 

分 类 号：Q78[生物学—分子生物学]