Construction of prokaryotic expression system of ureB gene from a clinical Helicobacter pylori strain and identification of the recombinant protein immunity

Figure 1 The target fragment of ureB gene amplified from H pylori strain Y06 DNA. Lane 1, 1 kb DNA marker (BBST); lanes 2 and 3, the target amplification fragment of ureB gene from genomic DNA of H pylori strain Y06; lane 4: blank control.

Figure 2 Homology comparison of the cloned and reported H pylori ureB nucleotide sequences. (1)-(3): the reported sequences from GenBank (No. NC000915, strain 26695; No. M60398, X57132; No. AB032429); (4): the sequencing result of H pylori strain Y06 ureB gene. Underlined areas indicate the positions of primer sequences.

Figure 3 Homology comparison of the putative amino acid sequences of the cloned and reported H pylori ureB gene. [1]-[3]: the reported sequences from GenBank (No. NC000915, strain 26695; No. M60398, X57132; No. AB032429); [4]: the putative amino acid sequence of the cloned H pylori strain Y06 ureB gene.

Figure 4 Expression of rUreB induced by IPTG at different concentrations. Lane 1, molecular mass marker; lanes 2-4, IPTG at 1.0, 0.5, and 0.1 mmol/L, respectively; lanes 5 and 6, bacterial precipitate and supernatant with IPTG at 1 mmol/L , respectively; lane 7, control.

Figure 5 Western blot result of commercial rabbit antibodies against the whole cell of H pylori and rUreB. Lane 1, rUreB; lane 2, blank.