植物甜蛋白des-pGlul-brazzein在大肠杆菌中表达条件的优化

Optimizing Culture Conditions for the Expression of des-pGlul-Brazzein in E.coli BL21(DE3)Pljys

构建了植物甜蛋白des—pGlul—Brazzein高效表达的工程菌株，对其IPTG诱导条件进行了研究。IPTG浓度、诱导时间和诱导温度对菌株生长和目的蛋白表达的试验结果显示，温度是重要的影响因素。进一步的研究表明，菌株在28～30℃以0．2mmol／L IPTG诱导4h，对菌株生长和目的蛋白的表达有利，目的蛋白的表达可达到总蛋白的43．8％。

Expression strain of des - pGlul- brazzein was constructed and the conditions used IPTG as inducer was also optimized. The effect of three factors which were IPTG concentration, induction time and temperature on growth of strain and on the yield of des - pGlul - brazzein was studied in detail. The result indicated that temperature was the most important factor. Further analysis showed the greater expressed level of des - pGlul - Brazzein, as high as 43.8 % of total cell protein,could be gained when stain was induced by 0.2mmol/L IPTG under 28-30℃ for 4h.