产单核细胞李氏杆菌hfq基因的原核表达及表达产物的聚合体分析

Prokaryotic expression of hfqgene fromListeria monocytogenes and polymers analysis of expressed Hfq protein

为了研究产单核细胞李氏杆菌Hfq蛋白的结构,将菌株yzuLM4的hfq基因在大肠杆菌中进行了表达。结果显示,在IPTG诱导下hfq基因获得可溶性表达,融合蛋白的大小约为16ku,诱导温度对表达的影响不显著。Western-blot分析结果表明,原核表达的Hfq蛋白具有反应原性。同时,通过非变性凝胶电泳,发现Hfq蛋白能以单体、二聚体、四聚体以及六聚体的形式存在,且各多聚体的比例不同。具有天然蛋白结构特征和免疫原性的Hfq蛋白的原核表达,为其在李氏杆菌中的功能研究奠定了基础。

To structurally analyze Hfq of Listeria monocytogenes, hfq gene from L. monocytogenes strain yzuLM4 was expressed in Escherichia coll. The predicted 16 ku soluble fusion protein His-Hfq was detected by SDS-PAGE after IPTG induction of recombinant bacteria, and the level of expression was not affected significantly by induction temperatures. Western-blot analysis showed that His-Hfq had reactionogenicity. There were 3 poly-meric forms of the His-Hfq protein,including dimer, tetramer and hexamer as shown by Native-PAGE. This study successfully expressed and purified Hfq protein with immunogenicity in E. coli, which could be used to explore the relationship between the structure and function of Hfq in L. monocytogenes.