Construction and expression of the plasmid vector of an outer envelope protein gene from the strong virulent Leptospira ,strain 017 in China
Objective Constuction of a recombinant plasmid expressing an outer envelope protein from the strong virulent Leptospira , serovar Lai strain 017. Methods The OmpL1 outer envelope protein gene was amplified from the genome of the Leptospira , strain 017. The removed OmpL1 gene was recombined with plasmid pBK CMV and the recombinant plasmid was selected according to the colour of bacterial colony and analysis of restriction enzymes. Then the OmpL1 gene was cut out from the recombinant plasmid and was cloned to plasmid pBV220 again. The recombinant plasmids with proper orientation was identified with analysis of restriction enzymes and DNA hybridization and selected . The host bacteria containing recombinant plasmids with proper orientation grew with heat induction , and the complete protein of the bacteria was extracted for SDS PAGE. Results Four recombinant plasmids with proper orientation, which ligated with pBV220, were obtained. One of the four recombinant plasmids, pBLM1, expressed a new protein with a weight of 33.5kD. Conclusions The success of construction and expression of recombinant plasmid pBLM1 has indicated that the OmpL1 gene obtained by PCR has a complete reading frame. And it supposes to be possible to use strain 017 for getting natural OmpL1 protein of Leptospira in quantity. The above work has laid a necessary foundation for future research on a new vaccine of Leptospira .