β-环糊精葡基转移酶的纯化方法及酶学性质的研究  

Purification and characterization of β-cyclodextrin glucanotransferase

作　　者：王媛[1] 王荫榆[2] 郭本恒[2] 张红发[2] 

机构地区：[1]上海水产大学食品学院,上海200090 [2]光明乳业股份有限公司技术中心,上海200072

出　　处：《工业微生物》2007年第6期7-11,共5页Industrial Microbiology

基　　金：国家科技支撑计划"十一五"奶业重大专项(2006BAD04A14)资助

摘　　要：β-环糊精葡基转移酶的粗酶液应用酚酞分光光度法测得该酶的环化活性为11．79U／mL。该粗酶液先经过淀粉-酒精沉淀或淀粉-硫酸铵沉淀初步纯化，然后经Sephacryl S-100凝胶层析后，比活力分别提高了16、21、50倍，由原来的11．44U／mg蛋白质增加到572．67U／mg蛋白质，回收率分别为72．4％、66．4％、40．9％，经SDS-PAGE电泳显示为单一的蛋白带，酶的分子量约为70kDa。酶学性质研究表明该酶的最适pH和最适温度分别为6．0和60℃，在pH6．0～10．0范围内，55℃以下保温30min基本保持稳定。纯化后的β-环糊精葡基转移酶的环化活性每克相当于35727U。The cyclization activity of the crude β-cyclodextrin glucanotransferase （β-CGTase）, determined by phenolphthalein spectrophotometric method, was 11.79U/mL. The enzyme was successively purified by starch-ethanol or starch-ammonium sulphate precipitation, and then Sephacryl S-100. The specific activity of the CGTase was increased 16-fold, 21-fold and 50-fold, from 11.43U/mg protein of the crude enzyme to 572.67U/mg protein of the purified CGTase with yield of 72.4 %, 66.4 % and 40.9 %, respectively. SDS-PAGE showed that the purified CGTase was homogeneous and the molecular weight was about 70kDa. Characterization of the enzyme exhibited that the optimum pH and temperature was 6.0 and 60℃ respectively and kept stable after 30 min maintenance below 55℃ from pH6.0 to 10.0. The cyclization activity of the purified β-CGTase was equivalent to 35727U per gram.

关 键 词：环糊精葡基转移酶 纯化 性质 

分 类 号：Q814[生物学—生物工程]