AIM:To construct a recombinant vector which can expressouter membrane protein (OMP) with M_r18 000 and heatshock protein A (HspA) from Helicobacter pylori (H.pylon)in E.coil BL21,and to exploit the possibility for obtainingthe vaccine conferring protection from H.pylori infection.METHODS:The target gene of HspA was amplified fromH.pylori chromosome by PCR,and then inserted into theprokaryotic expression vector pET32a (+) by restrictiveendonuclease enzyme kpn I,BamH I simultaneously.Therecombinant vector was used to sequence,and then togetherwith pET32a (+)/Omp_(18),digested by restrictive endonucleaseenzyme Hind Ⅲ and BamH Ⅰ simultaneously,pET32a(+)/HspA and Omp_(18) were recovered from 1% agarose gel bygel kit,and ligated with T4 ligase by BamH I digested viscidityend.The recombinant plasmid of pET32a(+)/HspA/Omp_(18)was transformed and expressed in E.coliBL21 (DE3) underinduction of IPTG.After purification,its antigenicity of thefusion protein was detected by Western blot.RESULTS:Enzyme digestion analysis and sequencingshowed that the target genes were inserted into therecombinant vector,composed of 891 base pairs,encodedobjective polypeptides of 297 amino acid residues.Comparedwith GenBank reported by Tomb et al,there were 1.3 %and 1.4 % differences in obtained H.pylori nucleotidesequence and amino acid residues,respectively.SDS-PAGEanalysis showed that relative molecule mass (M_r) of theexpressed product was M_r 51 000,M_r of protein expressedby pET32a (+) was about M_r 20 000,and soluble expressionproduct accounted for 18.96 % of total bacterial protein.After purification with Ni~(+2)-NTA agarose resins,the purificationof recombinant fusion protein was about 95 %.Westernblot showed that recombinant fusion protein could berecognized by the patients’ serum infected with H.pyloriand anti-Omp_(18) monoclone,suggesting that this protein hadgood antigenicity.CONCLUSION: The gene coding for H. pylori M_r18 000 OMP and HspA was cloned and expressed successfully. The results obtained lay the foundation for development of H. pylori protein vaccine and a quick diagnostic kit. AIM: To construct a recombinant vector which can expressouter membrane protein (OMP) with M_r18 000 and heatshock protein A (HspA) from Helicobacter pylori (H.pylon) in E. coli BL21, and to exploit the possibility for obtaining the vaccine conferring protection from H. pylori infection. METHODS: The target gene of HspA was amplified from H. pylori chromosome by PCR, and then inserted into the prokaryotic expression vector pET32a (+) by restrictive endonuclease enzyme kpn I, BamH I between. Consensus recombinant vector was used to sequence, and then together with pET32a (+) / Omp_ (18), digested by restrictive endonucleaseenzyme Hind III and BamH Ⅰ simultaneously, pET32a (+) / HspA and Omp_ (18) were recovered from 1% agarose gel by gel kit, and ligated with T4 ligase by BamH I digested viscidity and the recombinant plasmid of pET32a (+) / HspA / Omp_ (18) was transformed and expressed in E. coli BL21 (DE3) under induction of IPTG. After purification, its antigenicity of thefusion protein was detected byWestern blot.RESULTS : Enzyme digestion analysis and sequencing showed that the target genes were inserted into therecombinant vector, composed of 891 base pairs, encodedobjective polypeptides of 297 amino acid residues.Comparedwith GenBank reported by Tomb et al, there were 1.3% and 1.4% differences in obtained H. pylori nucleotide sequence and amino acid residues, respectively. SDS-PAGE analysis of that relative molecule mass (M_r) of the expressed product was M_r 51 000, M_r of protein expressed by pET32a (+) was about M_r 20,000, and soluble expression product accounted for 18.96% of total bacterial protein. After purification with Ni ~ (+2) -NTA agarose resins, the purification of recombinant fusion protein was about 95%. Westernblot showed that recombinant fusion protein could berecognized by the patients’ serum infected with H.pyloriand anti-Omp_ 18) monoclone, suggesting that this protein hadgood antigenicity. CONCLUSION: The gene coding for H. pylori M_r18 000 OMP and HspA was cloned and expressed successfully. Th e rresults obtained lay the foundation for development of H. pylori protein vaccine and a quick diagnostic kit.