牛多杀性巴氏杆菌外膜蛋白H的表达与纯化

Expression and Purification of Outer Membrane Protein H of P.multocida

试验对多杀性巴氏杆菌外膜蛋白H(OmpH)基因进行克隆、鉴定,并在原核系统中表达。以多杀性巴氏杆菌(CVCC448)强毒株基因组为模板,扩增OmpH基因,连接T载体,经测序鉴定正确后与表达载体pET-28a连接构建重组表达质粒OmpH-pET28a,将此重组质粒转化入表达宿主E.coli BL21菌株内,抽提质粒,酶切鉴定正确后对转化菌株以IPTG进行诱导,表达产物通过镍离子亲和层析纯化,之后进行SDS-PAGE和Western blotting分析。结果显示,OmpH基因的编码区为978bp,编码326个氨基酸残基,融合蛋白分子质量约为37ku。Western blotting检测结果显示,表达的重组蛋白OmpH可与鼠抗多杀性巴氏杆菌全菌体多抗血清反应得到清晰的目的条带,表明表达的重组蛋白具有良好的免疫原性。多杀性巴氏杆菌OmpH基因的成功表达,为进一步研究其免疫作用奠定了基础。

In this assay, cloning, expression and identification of outer membrane protein H （OmpH） of Pasteurella multo- cida were conducted to provide the foundation for study of immune effects of OmpH. OmpH gene was amplified from the ge- nomic DNA of P. multocida CVCC448 by using PCR. After being cloned into pMD18-T, OmpH-pMD18-T was sequenced to confirm its identity, and then cloned into expression vector pET-28a. The constructed recombinant plasmid OmpH-pET28a was transformed into E. coli BL21 and induced with IPTG, and the expressed product was identified by SDS-PAGE and West- ern blotting. Sequence analysis showed that the full coding length of OmpH was 978 bp, which could encode 326 amino acids, expressed recombinant protein was 37 ku. Western blotting result showed that recombinant OmpH could react with sera of rats immunized with P. multocida, which showed that the recombinant protein had good immunogenicities. OmpH-pET28a was constructed successfully, and fusion protein was expressed in E. coZi BL21 ,which laid the foundation for the study of immune effects of OmpH.