Cloning,expression and antigenicity identification of HSPA of Helicobacter pylori

Objective To construct recombinant plasmid containing HSPA of helicobacter pylori (Hp),sequence nucleic acid,express it in E.coli and study its antigenicity. Methods The gene encoding HSPA of Hp was amplified from Hp chromosomal DNA by PCR,then operated T-A cloned and sequenced. The gene was cloned into pGEX-4T-1 vector and expressed in E.coli. Expressed product was analyzed by Western blot and used to identify 29 strains of mouse monoclonal antibodies (mAbs) against Hp by ELISA. Results HSPA fragments were composed of 351 base pairs (GenBank submission No.DQ141574) and the nucleotide homology with other Hp strains was 96% ～ 98% . The recombinant HSPA-pGEX-4T-1 was expressed 41 ku fusion protein in E.coli. Western blot proved that the recombinant HSPA protein was specifically recognized by the serum of Hp-infected patients. 4 strains of 29 anti-Hp mouse mAbs were against HSPA. Conclusion The recombinant HSPA protein preserves original antigenicity and will be of value for vaccine study of Hp.