半乳糖苷酶基因在大肠杆菌中过量表达及IPTG诱导条件  

Overexpression of β-galactosidase Gene bga B in Escherichia coli and Studies on IPTG Induction

作　　者：陈卫[1] 葛佳佳[1] 张灏[1] 丁霄霖[1] 

机构地区：[1]江南大学食品学院,江苏无锡214036

出　　处：《无锡轻工大学学报（食品与生物技术）》2002年第5期492-495,共4页Journal of Wuxi University of Light Industry

摘　　要：从嗜热脂肪芽孢杆菌 (IAM 110 0 1)中克隆出编码热稳定的半乳糖苷酶蛋白基因bgaB ,构建具T7强启动子的pET 2 0 (b) bgaB质粒 ,并在大肠杆菌BL2 1(DE3)中进行表达 .经IPTG诱导后 ,重组菌周质中乳糖酶酶活达到 0 .12U /mL ,胞内酶活为 1.35U /mL ,比酶活为 6 .6 6U/mg蛋白 ,比酶源菌产生的酶活提高 5 0倍 .通过对IPTG诱导时机、诱导浓度和诱导时间的优化研究 ,重组菌产生的比酶活进一步提高至酶源菌的 90倍 .A thermostable β galactosidase gene bga B from Bacillus stearothermophilus (IAM11001)was cloned into pET 20(b) vector and expressed in Escherichia coli BL21(DE3). Expression was induced by IPTG, and the periplasmic and cytoplasmic enzyme activity reached 0.12 U/mL and 1.35 U/mL respectively. The specific activity of recombinant protein reached 6.66 U/mg protein, 50 fold higher than original strain. After optimizing of induction time, IPTG concentration and induction length, the enzyme activity increased to 90 times of original strain.

关 键 词：半乳糖苷酶基因 大肠杆菌 基因克隆 T7表达系统 诱导条件 

分 类 号：Q78[生物学—分子生物学]