摘要
由威海海域贝类肠道中分离出一株产胞外碱性蛋白酶的细菌,经16S rDNA分析鉴定为弧菌21Z1。该菌发酵液上清经60%饱和度的硫酸铵溶液沉淀、透析、Sephadex-G100分子筛层析等步骤,获得电泳纯的21Z1碱性蛋白酶,聚丙烯酰胺凝胶电泳(SDS-PAGE)显示其分子量约为31 kDa。酶学性质测定结果显示:该酶最适反应温度为40℃,在20~40℃稳定;最适反应pH为8.5,在pH=8.5~11.0间稳定;Na^+、K^+、Ca^(2+)、Mn^(2+)对该酶具有激活作用,Fe^(2+)、Fe^(2+)、Zn^(2+)及Cu^(2+)则不同程度地抑制其活性;该酶的耐盐性检测结果显示,在Na^+浓度为4 mol/L时,残余酶活在62%以上,表明21Z1碱性蛋白酶具有较强的耐盐性。
A strain was isolated from intestinal of shellfish in W eihai waters which could produce extracellular alkaine protease,and was identified as Vibrio sp.21Z1by16S rD N A analysis.The purified alkaine enzyme21Z1was obtained through ammonium sulfate precipitation,dialysed and Sephadex-GlOO column chromatography.Its molecular weight was determined as about31kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAG E)analysis.The results show that the optimal temperature of this enzyme is40T!,and it is stable at20?40T!.The optimal pH of this enzyme is8.5,and it is stable at pH ranging from8.5?11.0.N a+,K+,Ca2+,and M n2+have effect on its enzyme activity while Fe2+,Fe3+,Zn2+and Cu2+have various degrees of inhibition effect upon this enzyme.The salt tolerance test of enzyme21Z1exhibits the residual protease activity remains more than62%at4m o l/L concentration of N a+,so alkaine protease21Z1has good salt resistance.
作者
胡志恒
李玉梅
李强
HU Zhiheng;LI Yumei;LI Qiang(Schoolof Biological Science and Biotechnology, University of Jinan, Jinan 250022, China;Shandong Academy of Medical Sciences, University of Jinan, Jinan 250002, China)
出处
《济南大学学报(自然科学版)》
CAS
北大核心
2018年第1期77-82,共6页
Journal of University of Jinan(Science and Technology)
基金
新疆生产建设兵团塔里木盆地生物资源保护利用重点实验室开放课题(BRBY1405)
关键词
弧菌
碱性蛋白酶
纯化
酶学性质
耐盆性
Vibrio sp.
alkaline protease
purification
enzymatic characteristics
salt resistance