Construction and expression of prokaryotic expression vector for Schistosoma japonicum double membrane antigen fusion gene.

Objective To construct a recombinant prokaryotic expression vector for fusion gene encoding the membrane proteins SjTsp2 and Sj29 of Schistosoma japonicum (Sj)and express the recombinant protein. Methods SjTsp2 and Sj29 fusion gene was amplified by SOEing PCR and cloned into prokaryotic expression vector pET32a. The constructed recombinant plasmid was transformed to E. coli BL21(DE3)for expression under induction of IPTG. The expressed product was identified by SDS-PAGE and Western blot. Results Sequencing proved that both the homologies of the fusion gene to two target genes were 100%. SDS-PAGE proved that the expressed product, with a relative molecular mass of 43 000, contained more than 20% of total somatic protein. Western blot showed specific bindings of the expressed product to the McAbs against SjTsp2 and Sj29 proteins. Conclusion A recombinant prokaryotic expression vector for SjTsp2 and Sj29 fusion gene was successfully constructed and expressed in E. coli, which provided a material for development of Sj vaccine.