Cloning, Expression and Antigenicity of UreaseA of Helicobacter pylori

Objective Construction and expression of a recombinant plasmid containing UreaseA(UreA) of Helicobacter pylori (Hp) NCTC11639 strain. Methods The gene encoding UreA of Hp was amplified from Hp chromosomal DNA by PCR. The sequence of UreA was determined using pMD18-T vector. Expression was achieved by cloning the gene into pGEX-4T-1 expression vector and expressed in E.coli. Immuno-reactivity of the recombinant protein to mouse monoclonal antibodies (mAbs) against Hp was determined by Western-blot. Results A gene fragment of 675 base pairs (DQ141577) was amplified. The sequence of UreA shared 95%～98% of nucleotide homology with the same gene of other stains of Hp in GenBank. Results from Western blotting analysis showed that the recombinant UreA protein (mol. wt. 52 kDa) reacted with the serum obtained from Hp-infected patients or the Hp immunized BAlB/c mice. In addition, UreA also reacted with 4 out of 29 anti-Hp mouse mAbs. Conclusion The recombinant UreA is immunogenic and it may further be developed for clinical diagnosis and the development of vaccine for Hp.