乳糖诱导家蚕抗菌肽在大肠杆菌中的融合表达

根据家蚕抗菌肽Cecropin B的氨基酸序列,按大肠杆菌基因偏爱密码子,人工合成改造过的Cecropin B基因。将改造过的Cecropin B基因克隆到大肠杆菌表达载体pET-41a中,构建了融合蛋白表达载体pET41a-cecB,转化大肠杆菌BL21(DE3),得到表达Cecropin B的大肠杆菌工程菌株。通过SDS-PAGE分析,研究了用乳糖代替IPTG诱导大肠杆菌BL21表达家蚕抗菌肽Cecropin B的诱导条件,得到乳糖的最佳用量为0.25 mmol/L、诱导起始浓度为OD 1.0、诱导时间为5 h。最终Cecropin B的表达量可占细胞总蛋白的17.1%。为乳糖作为诱导剂应用于大肠杆菌生产重组家蚕抗菌肽提供了参考依据。

Fusion Expression of Cecropin B in Escherichia coli with Lactose as the Inducer

According to the amino acid sequence of Cecropin B and the bias coden for genes of Escherichia coli,the Cecropin B gene was artificial synthesized and subcloned into an E.coli expression vector pET-41a.The recombined plasmid pET41a-cecB was then transformed into E.coli BL21(DE3).Lactose was used as an inducer instead of IPTG.Detected by SDS-Page,the result demonstrated that the proper optimization of induction conditions is to add 0.25 mmol/L(termical concentration) lactose at OD 1.0 and induce 5 h.The pET4...