鸭leptin基因在大肠杆菌中的融合表达及生物学活性分析

 【目的】研究鸭leptin在体外高效表达特点，探讨表达产物的生物学活性及其功能。【方法】构建重组鸭leptin基因原核表达菌株，重组菌株经不同浓度IPTG和不同时间诱导后，对表达蛋白进行提取、纯化、复性和浓缩，经注射昆明小鼠后，对小鼠的体重﹑采食量和体脂含量进行分析。【结果】鸭leptin在大肠杆菌中实现了高效特异性融合表达，融合蛋白分子量约为20 kD，其中16 kD为鸭leptin基因表达产物，目的蛋白在0.2 mmol?L-1 IPTG的诱导下，表达量最高约占菌体总蛋白的57%。重组蛋白纯化﹑复性﹑浓缩后，能够明显降低小鼠摄食量、体重和体脂含量。【结论】鸭leptin基因在大肠杆菌中进行了高效融合表达，表达产物具有明显的生物学活性。

Fusion Expression of Duck leptin Gene in Escherichia coli and Determination of Recombinant Protein Bioactivity

Abstract:【Objective】To investigate the expression characteristic of duck leptin in E.coli BL21 and the bioactivity of the expression product.【Method】Constructive the recombinant duck leptin gene prokaryotic expression strain. The recombinant strain was induced in different time and different concentrations of IPTG. After purification, renaturation and condensation, the product was injected into Kunming mice. The body weight, food intake and body weight of mice were analyzed.【Result】The fusion protein was specifically expressed. The results of SDS-PAGE analysis indicated that the molecular weight of the fusion protein was about 20kDa, which included the 16kDa protein expressed from duck leptin gene. The aimed protein was expressed with the induction of 0.2mmol/L IPTG, which was about 57% of total protein in bacteria. The recombinant protein reduced body weight、food intake and body weight on the testing in Kunming mice.【Conclusion】Duck leptin was high effective in E.coli BL21. The purified recombinant protein was proved to be biologically activity.