重组人胸腺素α1融合蛋白在大肠杆菌中表达条件的优化

为提高人胸腺素α1（Tα1）融合蛋白在大肠杆菌中的表达量，研究了本实验室构建的pET39-Tα1重组质粒在E.coli BL21（DE3）宿主菌中的表达条件。经SDS-PAGE和凝胶成像系统GDS-8000分析结果表明，重组菌以LB为培养基，卡那霉素浓度为50mg／L，开始诱导时的菌体密度为（OD600=0．5，所加IPTG的浓度为0．5mmol／L，27．5℃摇床200r／min振荡诱导培养10h时，可在周至空间中获得高效表达的可溶的Tα1融合蛋白，占周质蛋白总量的64．7％，为下一步纯化工作提供了方便。

Optimization of Recombinant Human Thymosin alpha 1 Fusion Protein Expression in E.coli

To improve the expression level of human thymosin alpha 1 (Tα1)fusion protein, the growth condi tions of the engineering strain confirmed by transforming the recombinant plasmid pET39 Tα1 constructed by our team into the host E. coli BL21 (DE3) were studied, which remarkably influenced the final yield of protein expression. With the aid of SDS-PAGE and Electrophoresis Gel Imaging System GDS-8 000 analysis, it was found that the best expression condition was that the induction start as OD600 reached about 0. 5 by adding IPTG to a final concentration of 0. 5 mmol/L and then continued incubation for 10 hours at 27.5℃ (200 r/min) in the LB medium containing 50 mg/L kanamycin with shaking flasks. The maximum yield of fusion protein was about 64.7%00 of the total mass of periplasmic proteins. Furthermore the soluble form of the target protein makes convenience for next purification work.