H5N1-NP蛋白的原核表达及与宿主蛋白相互作用的初步研究

目的 原核表达并纯化禽流感病毒A/Anhui/1/2005（H5N1）的NP蛋白,并筛选人支气管上皮BEAS-2B细胞总蛋白中能够与纯化的NP蛋白相互作用的蛋白.方法 一方面,构建了含有NP基因的原核表达质粒pET30a-NP,并在大肠埃希菌中获得了可溶性表达.亲和层析和离子交换层析两步对NP蛋白进行纯化.另一方面,制备了BEAS-2B细胞总蛋白.在此基础上,联合应用Pull-down与LC-MS/MS技术来筛选并确认细胞中与纯化的NP蛋白相互作用的成分.结果 构建的pET30a-NP质粒在IPTG诱导下在原核细胞中实现了可溶表达,经过两步纯化后,得到可溶的NP蛋白纯品.Pull-down与LC-MS/MS技术初步筛选到BEAS-2B细胞中20个可能与NP蛋白相互作用的细胞蛋白.还需要进一步的实验来验证他们和NP蛋白之间的相互作用.结论 获得了高纯度的可溶NP蛋白及筛选到20个可能与其相互作用的BEAS-2B细胞候选蛋白.

Expression and purification of avian influenza virus H5N1 NP protein, and screening interaction proteins of host cells in vitro

Objective To express and purify H5N1 influenza virus (A/Anhui/1/2005) NP in prokaryotic system and to explore the NP-interacting proteins of human bronchial epithelial cells BEAS-2B in vitro . Methods The full length H5N1 NP gene fragment was amplified by PCR, inserted into prokaryotic expression vector(pET30a) to generate NP expression plasmid pET30a-NP. After transforming pET30a-NP into E. coli (BL21), the expression of soluble NP protein was induced by IPTG. The expressed NP protein was purified by two steps with metal chelation chromatography and ion exchange chromatography. Then the total proteins of BEAS-2B cells was extracted for screening the components which have protein-protein interaction with purified NP by pull-down and LC-MS/MS methods. Results The expression of H5N1 NP protein could be induced by IPTG in bacterial system using expression plasmid pET30a-NP. The soluble NP was purified. Twenty proteins were found by pull-down and LC-MS/MS, the further experiments may be needed to prove protein-protein interaction between them. Conclusion The soluble H5N1 NP fusion protein with high purity was obtained and twenty proteins were found which could interact with it by pull-down and LC-MS/MS.