Cloning and expression of urease B subunit (UreB) of Helicobacter pylori / 中华检验医学杂志

ABSTRACT

Objective To obtain the recombinant urease B subunit (ureB) of Helicobacter pylori (Hp) and apply it in serological detection of Hp infected patients. Methods Urease B subunit gene was amplified from the complete genome of Helicobacter pylori by PCR, and cloned into the PinPoint TM Xa Ⅲ fusion expression vector, then was sequenced. The protein of urease B subunit was expressed in E.coli JM109 and purified with affinity chromatography. 113 serum samples of peptic ulcer patients were detected by ELISA combined with purified UreB protein. Results DNA sequence analysis showed the nucleic acid sequence homology of ureB gene was 96.44% and the putative amino acid sequence homology was 99.65%. The recombinant UreB protein was composed of 571 amino acid residues and kept original immunologic reaction with corresponding antibody, and its purity was over 90% after affinity chromatography. The results of ELISA associated with recombination UreB antigen showed the sensitivity and specificity was 92%, 98.5%. Conclusion The recombinant UreB protein will be of value for clinical serodiagnosis and epidemiological study of Helicobacter pylori.