摘要
从高温土壤中分离得到的一株产耐热中性蛋白酶的嗜热芽孢杆菌,该菌分泌的胞外蛋白酶粗酶液经80%饱和度硫酸铵沉淀、DEAE-Sepharose Fast Flow阴离子交换层析和Superdax75凝胶层析分离纯化后,纯化倍数提高4．36倍,得率为5．3%,经SDS-PAGE电泳测得其分子量为30．6kDa。酶的最适温度与pH实验表明,该酶最适温度为65℃、最适pH为7．5,并且该酶在50℃时表现出1h以上的稳定性。该蛋白酶的活性受到丝氨酸族蛋白酶专一性抑制PMSF和金属离子螯合剂EDTA强烈抑制,Zn^(2+)能提高酶活性,因此该蛋白酶为Zn^(2+)激活的丝氨酸族蛋白酶。
A Thermophilic Bacillus strain for secreting thermostable neutral protease was isolated from high temperature soil sample. The purification steps included 80% saturated ammonium sulfate sedimentation fast, then with DEAE-Sepharose fast flow anion exchange chromatogram and Superdax 75 gel filtration on AKTA purification 100 protein liquid chromatogram system, and the final purification-fold 4.36 and recovery rate 5.31% were obtained. The molecular mass 30.6kDa was estimated by SDS-PAGE. The optimal pH and the protease temperature were 7.5 and 65℃, respectively. The protease was stable at 50℃ during for 1 h incubation. The protease was inhibited markedly by serine protease inhibitor PMSF（phenylmethylsulfonyl fluoride） and metal ion chelator EDTA（ethylene diamine tetraacetic acid）. Andalso the protease activlly is enhanced by Zn^2＋. So the protease belongs to Zn^2＋ activated serine protease.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2007年第4期179-182,共4页
Food Science
基金
浙江省自然科学基金项目(Y405083)
浙江科技计划项目(2005C32019)
关键词
中性蛋白酶
纯化
特性
嗜热芽孢杆菌
丝氨酸族蛋白酶
neutral protease
pudfication
characteristic
Thermophilic Bacillus
serine protease
