Prokaryotic expression of fusion gene of vacuolating segment of vacA and hpaA in Helicobacter pylori

Abstract

AIM: The prokaryotic expression vector of the fusion gene with v segment of the vacuolating cytotoxin and hpaA of Helicobacter pylori (H pylori) was constructed and expressed. It would lay a foundation for prophylaxis and therapy of H pylori infection. METHODS: By using the primer with a fragment encoding 12 amino acids of N-terminal of human interleukin-3 (IL-3), the vacuolating cytotoxin gene of Hp with linker was amplified from pQE30-V plasmid by PCR. The gene was cloned into plasmid pTrc99A-HpaA and fused with the hpaA gene. The fusion gene was cloned into prokaryotic expression vector pQE30. The recombinant plasmid of pQE30-V-HpaA was transformed into E.coli. DH5α and expressed in the presence of IPTG. The expression product was analyzed by SDS-PAGE, its antigenicity of the expression product was identified by Western blotting. RESULTS: Mr of recombinant protein was about 65 000 and represented 35% total protein of E.coli. Western blotting showed the recombinant protein could be recognized by the antiserum against H pylori. CONCLUSION: The fusion gene and its prokaryotic expression vector pQE30-V-HpaA is constructed and expressed in DH5α successfully. It provides the antigen basis for further studying the biological function of fusion protein and obtaining vaccine against the infection of H pylori.