Enterococcus faecalis RQ15产低温中性蛋白酶的纯化及酶学性质  

Purification and Characterization of Cold-adapted Neutral Protease from Enterococcus faecalis RQ15

作　　者：朱巍巍[1] 李杨[1] 朱万琴[1] 王艳华[1] 冀宝赢[1] 孙翠焕[1] 

机构地区：[1]辽宁省微生物科学研究院,辽宁朝阳122000

出　　处：《食品科学》2011年第11期239-242,共4页Food Science

摘　　要：采用DEAE Sepharose Fast Flow和SuperdexTM 75对Enterococcus faecalis RQ15产蛋白酶进行纯化和酶学性质研究。SDS-PAGE测定该蛋白酶分子质量为32.4kD,最适作用温度35～40℃,最适pH7.5。20～40℃之间酶活较高,pH值耐受范围广泛,具有低温蛋白酶的特征。Zn2+对蛋白酶有激活作用,Ag+、Hg2+和EDTA-Na2对酶有显著抑制作用。纯酶最适作用条件下对酪蛋白底物的Km和Vmax分别为1.31×10-4mol/L和6.92×10-6mol/(L.s)。The protease from Enterococcus faecalis RQ15 was characterized after purification with DEAE Sepharose Fast Flow and SuperdexTM 75.The molecular weight of the protease was determination by SDS-PAGE to be 32.4 kD.The optimal reaction temperature and pH of protease were 35—40 ℃ and 7.5,respectively.The protease was characterized to be a cold-adapted enzyme.It had more activity at 20—40 ℃ and a wide range of pH tolerance.The activity of the protease could be activated by Zn2＋ but inhibited by Ag＋,Hg2＋ and EDTA-Na2 significantly.The Km and Vmax of the purified protease were 1.31 × 10-4 mol/L and 6.92×10-6 mol/（L·s）,respectively.

关 键 词：Enterococcusfaecalis 低温蛋白酶 纯化 

分 类 号：Q939.117[生物学—微生物学]