响应面分析法优化重组原动蛋白2β诱导条件的研究

Determination of Optimal Induction Conditions by Response Surface Methodology: the Case of Recombinant Prokineticin 2β

原动蛋白2β(PK2β)是近年新发现的一个选择性激活PKR1的蛋白质因子。采用响应面分析法(RSM)研究了利用重组BL21(DE3)表达PK2β的最优诱导条件。结果表明,诱导时机与诱导物浓度对PK2β的表达水平具有显著性影响,但诱导时间不具有显著性影响。试验数据拟合与极值分析表明最优诱导条件为工程菌OD600为0.50时,采用终浓度为0.11 mmol/L的IPTG在37℃诱导培养7.73 h,此时PK2β表达水平可达242.78 mg/L。验证试验结果表明,重组PK2β的表达水平比优化前提高了46%,而IPTG的用量减少了89%,有利于大量制备该蛋白质进行后续功能研究及应用研究。

Prokineticin 2β （ PK2β ） has been recently identified as a selective ligand for PK receptor 1. Herein, response surface methodology（ RSM ）was applied to optimize induction conditions for high level expression of PK2β by recombinant Escherichia coli BL21（ DE3 ）. The results showed that time-point of induction and inducer concentration had significant effects on yield of recombinant PK2β. The optimal induction conditions were as follows ： OD600 0.50 for induction-starting cell density, 0.11 mmol/L for IPTG concentration and 7.73 h for postinduction time. The maximum yield of PK2β in shake flask experiment reached 242.78 mg/L when engineering bacteria were cultured under the optimal conditions. The results of verification experiments showed that the yield of PK213 was 46% higher than that before optimization and the usage of IPTG was saved up to 89% than the previous usage. The results will be helpful for large-scale preparation of PK2β for further function and application study.