Cloning and Expression of Helicobacter Pylori UreB122 (a Segment of the B-subunit of Urease Gene)

Introduction: Helicobacter pylori is associated with the chronic gastritis, peptic ulcer, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Moreover, antibiotic therapies do not protect against potential re-infection while have risk for development of drug resistance. Therefore, vaccine-mediated protection against H. pylori became an attractive clinical interest. H. pylori urease plays an important role in survival and pathogenesis of the infection. In this study the UreB122 (aa143-264) gene cloned in pET expression vector and the recombinant protein (rUreB122) was over expressed in Escherichia coli (E. coli .( Patients and Methods: Genomic DNA of the standard H. pylori strain 26695 was isolated as the template and UreB122 gene was amplified by PCR. Prokaryote expression vector pET32a was inserted with UreB122 gene (pET32a- UreB122). The recombinant plasmid was used to transform competent E. coli DH5?, and positive clones were selected. Then the recombinant plasmid was used to transform E. coli BL21DE3 for expression of recombinant protein UreB122. The expression of recombinant protein was induced by isopropythio-B-D-galctoside (IPTG) at different concentration and examined by SDS-PAGE. Western blot assay was used to determine immunoreactivity of rUreB122 by anti His- Tag antibodies against recombinant UreB122 . Results: In comparison with the reported corresponding sequences, the nucleotide sequence homology of UreB122 gene was 99.9%. UreB122 fusion protein was able to react with the anti His-Tag antibody . Conclusion: A prokaryotic expression system with high efficiency of H. pylori UreB122 gene was successfully established and UreB122 fusion protein showed satisfactory immunoreactivity. These results indicate that production of specific recombinant protein is an alternative and potentially more expeditious strategy for development of H. pylori vaccine