小鼠Rig-Ⅰ蛋白的原核表达、纯化及其抗体制备

Prokaryotic expression and purification of the Mus musculus Rig-Ⅰ protein and preparation of antibody

【目的】进一步研究小鼠维甲酸诱导基因Ⅰ(Rig-Ⅰ)蛋白的细胞信号传导、结构与功能。【方法】利用已经构建好的逆转录病毒载体MigRI-Rig-Ⅰ,用PCR方法扩增出小鼠Rig-Ⅰ基因氨基端100 bp长度的片断(Rig-Ⅰ-N),将此片段定向克隆到原核表达载体pGEX-4T2中,构建pGEX-4T2-Rig-Ⅰ-N,再将Rig-Ⅰ基因剩余部分克隆到已构建有Rig-Ⅰ-N部分片段的pGEX-4T2-Rig-Ⅰ-N中,构建融合表达载体pGEX-4T2-Rig-Ⅰ,将其转化大肠杆菌BL21,经IPTG诱导表达,对表达产物GST-Rig-Ⅰ融合蛋白进行纯化,制备抗体,并对抗体效价进行ELISA检测及抗体特异性的Western blot分析。【结果】重组蛋白GST-Rig-Ⅰ能在大肠杆菌中表达,表达的融合蛋白GST-Rig-Ⅰ纯化和洗脱后分子质量为130 ku,纯度>90%,制备的抗体效价达到1∶625 000,并且能够识别在原核表达系统以及真核细胞内表达的小鼠Rig-Ⅰ蛋白。【结论】建立的表达系统能够表达重组蛋白GST-Rig-Ⅰ,制备的抗体具有良好的免疫特异性。

【Objective】 The study was done to study the signal transduction,structure and function of the protein of mouse retinoic acid-induced geneⅠ（Rig-Ⅰ）.【Method】 On the basis of the constructed retrovirus plasmid MigRI-Rig-Ⅰ,the N-terminal 100 bp sequences of the mouse Rig-Ⅰ（Rig-Ⅰ-N） were amplified and cloned into the prokaryotic expression vector pGEX-4T2,formed recombinant plasmid pGEX-4T2-Rig-Ⅰ-N,the residual sequences of Rig-Ⅰ were cloned into the plasmid pGEX-4T2-Rig-Ⅰ-N to generate the recombinant expression plasmid pGEX-4T2-Rig-Ⅰ. After transforming the Escherichia coli BL21, the fusion protein was induced, purified and used to immunize rabbit,and the antibody＇s titer and specificity were detected with ELISA and Western blot respectively. [Result] The fusion protein GST-Rig- Ⅰ could be expressed in the Escherichia coli,the relative molecular mass of fusion protein was 130 ku,the purity more than 90 % ,the titer of antibody could reach 1： 625 000 and recognize the Rig-Ⅰ protein expressed from the prokaryotic system and eukaryotic cell. [Conclusion] Expression system pGEX-4T2-Rig-Ⅰ could express recombinant protein GST-Rig- Ⅱ ,and antibody prepared had a good immunized specificity.