Cloning and expression of the CagA gene of Helicobacter pylori and the gene of cholera toxin subunit B
Objective To construct the recombinant plasmid of Helicobacter pylori(Hp) CagA and mucasal adjuvant cholera toxin subunit B (CTB) and express fusion proteins in E.coli JM109DE3. Methods Gene encoding CagA was amplified from Hp chromosomal DNA and CTB from Vibrio cholerae. The genes were inserted into the prokaryotic expression vector pGEMEX-1. Recombinant CagA and CTB were expressed in E.coli JM109DE3. Results The DNA sequence of recombinant pGEMEX-CTB was identical with that published by GenBank publicized. The relative molecular mass (M r) of fusion protein was corresponding to the M r shown in SDS-PAGE. Western blot analysis of the recombinant CagA confirmed its strong immunogenicity. Conclusion The recombinant protein may function as a potential vaccine or as a diagnostic antigen.