巨大芽孢杆菌产胞外核糖核酸酶的分离纯化及部分酶学性质研究  

Purification and Partial Characterization of Extracellular Ribonuclease from Bacillus megaterium

作　　者：赵芯[1] 成丽丽[1] 邓玉[1] 敬海明[1] 唐云明[1] 

机构地区：[1]西南大学生命科学学院,重庆市甘薯工程研究中心,三峡库区生态环境教育部重点实验室,重庆400715

出　　处：《食品科学》2012年第19期254-258,共5页Food Science

基　　金：重庆市科学技术委员会重点攻关项目(CSTC,2011AB1027)

摘　　要：巨大芽孢杆菌发酵液经硫酸铵沉淀、CM-Sepharose离子交换层析和Superdex-200凝胶过滤层析,纯化得到核糖核酸酶电泳纯品,并对其性质进行研究。该酶比活力为54272.27U/mg,回收率为11.37%,纯化倍数为606.67倍。该酶分子质量约为33.3kD,最适温度为52.5℃,最适pH值为8.5,在20～40℃以及pH6.0～7.0范围内稳定性较好。Fe2+、Cu2+、SDS、抗坏血酸和草酸对该酶活性有抑制作用。After amonanium sulfate precipitation followed by ion-exchange chromatography on CM-Sepharose column and Superdex-200 gel-filtration, ribonuclease from Bacillus megaterium was purified to electrophoretic homogeneity. Some of its enzymological properties were then explored. The results showed that the enzyme was 606.67-fold purified with specific activity of 54272.27 U/mg and recovery rate of 11.37%. The molecular weight was 33.3 kD. Optimum activity of the enzyme was achieved at 52.5 ℃ and pH 8.5. The enzyme displayed good stability at 20-40 ℃ and pH 6.0-7.0. The activity of this enzyme was inhibited by Fe^2＋, Cu^2＋, SDS, ascorbic acid and oxalic acid.

关 键 词：巨大芽孢杆菌 核糖核酸酶 分离纯化 性质 

分 类 号：Q556.1[生物学—生物化学]