人白细胞介素26的基因克隆及其在大肠杆菌中的表达

克隆人白细胞介素-26(human interleukin-26,hIL-26)基因,构建高效稳定的大肠杆菌表达菌株。对GenBank上报道的hIL-26基因进行序列分析后设计合成引物,利用RT-PCR技术从人外周血单个核细胞(PBMC)总RNA中反转录并扩增得到人成熟肽IL-26基因。将得到的基因克隆到pMD18-T载体中,菌落PCR筛选、酶切鉴定并进行DNA序列分析。用BamHI和EcoRⅠ将目的片段切下,插入表达载体pBV220相应的位点。42℃热诱导表达目的蛋白,SDS-PAGE分析显示表达蛋白约占菌体总蛋白的20%,Western印迹法证实重组蛋白为特异性蛋白,分子筛纯化后纯度达90%以上。表达的重组蛋白经谷胱甘肽复性缓冲液复性,用RT-PCR检测复性的重组蛋白能促进PBMC合成IFN-γ。

Cloning and Expression of Human Interleukin-26 in Escherichia coli

To clone human interleukin-26 (hIL-26) and express it in E. coli efficiently. Two pairs of primers were synthesized according to the hIL-26 gene reported on GenBank. The hIL-26 gene was cloned by nest PCR following the first round RT-PCR from human peripherial blood monocytes total RNA, and then the PCR product was cloned into pMD18-T vector. Colony PCR, restriction analysis and sequence analysis showed that the gene cloned was the same as the reported hIL-26. The recombinant was cut with BamHI and EcoR I to obtain the hIL-26 fragment, and then the fragment was inserted into pBV220 which was cut with the same enzymes. The recombinant expression vector was induced to express hIL-26 at 42 degrees C, SDS-PAGE analysis showed that the recombinant protein accounted for up to 20% of the whole protein of E. coli, and the protein was also confirmed by Western blotting. Purity of the protein was found to be above 90% after purified with molecular sieve. After renaturalized with glutathione buffer, the promoting effect of it on the production of IFN-y in PBMC was detected by RT-PCR. A recombinant bacterial strain for expressing hIL-26 with biological activity was constructed successfully.