温度诱导模式对重组大肠杆菌质粒拷贝数的影响

Effects of Temperature Induction Modes on the Plasmid Copy Number in Escherichia coli

对于大肠杆菌温度表达系统,温度的选择和变化对外源基因的表达至关重要,最直接的因素表现在对质粒拷贝数的影响上。本文通过重组大肠杆菌DH 5α表达载脂蛋白A I-M ilano来分析不同温度诱导模式对质粒拷贝数的影响,确立了二次升温诱导(30°C→42°C→37°C→42°C)有利于菌体质粒拷贝数的增加,从而提高目的蛋白的表达量,结果表明:二次升温诱导比一次升温诱导蛋白表达量增加80%。

Study on the temperature induction system of E. coli shows that the choice and change of induction temperature is important to heterologous gene expression, and the direct factor is shown in the effect on the plasmid copy number. This study focuses on effects of different temperature induction modes on the plasmid copy number using recombinant DH5a to express proapo AI-Milano. A novel two-step temperature-upshift induction is proved to be valuable in improving plasmid copy number, resulting in the significant enhancement of the expression level of recombinant protein.