Abstract: Objective To clone and express the Clonorchis sinensis F₀-ATP synthase b chain （CsF₀-ATP-synt_B） gene and analyze immunogenicity of the recombinant protein. Methods The coding region F₀-ATP synthase b chain gene with the mitochondrial targeting sequence （MTS） removed was amplified with PCR using the cloned plasmid as template， and the product was cloned into the prokaryotic expression vector pET-28a（+）， transformed into E.coli BL21（DE3） and induced with IPTG. The expressed product was purified by Ni-IDA affinity chromatography，and analyzed by SDS-PAGE for its expression and identified by Western blotting for its immunogenicity. Results The coding sequence of the F₀-ATP synthase b-chain like gene removed off the MTS contains 813 base pairs encoding 271 amino acids with a theoretical molecular weight of 31 171.9. PCR， double enzyme digestion and DNA sequencing confirmed that the recombinant plasmid pET-28a（+）-CsF0-ATP-synt_B was constructed successfully， and the resoluble expression was obtained in E.coli BL21. Highly purified recombinant protein was prepared through affinity chromatography. The recombinant protein could be recognized by the immune serum of the SD rat immunized with the recombinant protein. Conclusion The CsF₀-ATP-synt_B like gene has been efficiently expressed in prokaryotic expression system with immunogenicity.

Key words: Clonorchis sinensis, F₀-ATP synthase b chain, Molecular cloning, Prokaryotic expression, Immunogenicity