钩端螺旋体LAg42膜蛋白基因的克隆及原核表达

分别以问号状赖型钩体017株，56601株及双曲钩体PatocI株基因组为模板，PCR扩增目的基因lag42与质粒pET32a(＋)构建重组原核表达质粒，在大肠杆菌BL21中诱导表达.结果显示不同毒力赖型钩体均能扩增出约1100 bp的片段，而PatocI株则未能扩增出目的片段；不同赖型钩体的lag42基因的同源性很高.融合表达质粒pET-lag42转化大肠杆菌BL21后，经IPTG诱导，表达出约62kDa的重组融合蛋白，用Western blotting证实其有良好的抗原性，纯化蛋白免疫新西兰大白兔，获

Cloning and prokaryotic expression of the LAg42 membrane protein gene of Leptospira interrogans serovar Lai

The lag42 gene was amplified by PCR from genome of L.interrcgans Lai 017 strain 56601 strain and L.bilexa PatocI strain.About 1100 bp fragment was amplified in various viruLent L.interrcgans serovar Lai,but not in L.bilexa PatocI strain.There was a high homology of DNA sequence of the lag42 in various L.interrcgans Lai.The amplified DNA fragment was then cloned into vector PET32a(+) and DNA sequence was performed subsequently.The recombinant plasmid PET-lag42 was then transformed into E.coli BL21 to be induced with IPTG and expressed the 62kDa fusion protein His-LAg42.It's antigenicity was confirmed by Western blotting.The expression product was purified and immunized the New Zealand rabbits.