Ya-Fei Mao1, Jie Yan. 1. Department of Medical Microbiology and Parasitology, College of Medical Science, Zhejiang University, 353 Yanan Road, Hangzhou 310031, Zhejiang Province, China.
Abstract
AIM: To clone ureB gene from a clinical isolate of Helicobacter pylori and construct a prokaryotic expression system of the gene and identify immunity of the expressed recombinant protein. METHODS: ureB gene from a clinical H pylori strain Y06 was amplified by the high fidelity polymerase chain reaction technique. The target DNA fragment amplified from ureB gene was sequenced after T-A cloning. Prokaryotic recombinant expression vector pET32a inserted with ureB gene (pET32a-ureB) was constructed. The expression of recombinant UreB protein (rUreB) in E. coli BL21DE3 induced by isopropylthio-beta-D-galactoside (IPTG) at different concentrations was examined by SDS-PAGE. Western blot using commercial antibodies against whole cell of H pylori and an immunodiffusion assay using a self-prepared rabbit anti-rUreB antibody were applied to determine immunity of the target recombinant protein. ELISA was used to detect the antibody against rUreB in sera of 125 H pylori infected patients and to examine rUreB expression in 109 H pylori isolates. RESULTS: In comparison with the reported corresponding sequences, the nucleotide sequence homology of the cloned ureB gene was from 96.88-97.82% while the homology of its putative amino acid sequence was as high as 99.65-99.82%. The rUreB output expressed by pET32a-ureB-BL21DE3 was approximate 30% of the total bacterial proteins. rUreB specifically combined with the commercial antibodies against whole cell of H pylori and strongly induced rabbits to produce antibody with a 1:8 immunodiffusion titer after the animals were immunized with the recombinant protein. Serum samples from all H pylori infected patients were positive for UreB antibody and UreB expression were detectable in all tested H pylori isolates. CONCLUSION: A prokaryotic expression system with high expression efficiency of H pylori ureB gene was successfully established. The expressed rUreB showed qualified immunoreactivity and antigenicity. High frequencies of UreB expression in different H pylori isolates and specific antibody against UreB in sera of H pylori infected patients indicate that UreB is an excellent antigen candidate for developing H pylori vaccine.
AIM: To clone ureB gene from a clinical isolate of Helicobacter pylori and construct a prokaryotic expression system of the gene and identify immunity of the expressed recombinant protein. METHODS: ureB gene from a clinical H pylori strain Y06 was amplified by the high fidelity polymerase chain reaction technique. The target DNA fragment amplified from ureB gene was sequenced after T-A cloning. Prokaryotic recombinant expression vector pET32a inserted with ureB gene (pET32a-ureB) was constructed. The expression of recombinant UreB protein (rUreB) in E. coli BL21DE3 induced by isopropylthio-beta-D-galactoside (IPTG) at different concentrations was examined by SDS-PAGE. Western blot using commercial antibodies against whole cell of H pylori and an immunodiffusion assay using a self-prepared rabbit anti-rUreB antibody were applied to determine immunity of the target recombinant protein. ELISA was used to detect the antibody against rUreB in sera of 125 H pylori infectedpatients and to examine rUreB expression in 109 H pylori isolates. RESULTS: In comparison with the reported corresponding sequences, the nucleotide sequence homology of the cloned ureB gene was from 96.88-97.82% while the homology of its putative amino acid sequence was as high as 99.65-99.82%. The rUreB output expressed by pET32a-ureB-BL21DE3 was approximate 30% of the total bacterial proteins. rUreB specifically combined with the commercial antibodies against whole cell of H pylori and strongly induced rabbits to produce antibody with a 1:8 immunodiffusion titer after the animals were immunized with the recombinant protein. Serum samples from all H pylori infectedpatients were positive for UreB antibody and UreB expression were detectable in all tested H pylori isolates. CONCLUSION: A prokaryotic expression system with high expression efficiency of H pylori ureB gene was successfully established. The expressed rUreB showed qualified immunoreactivity and antigenicity. High frequencies of UreB expression in different H pylori isolates and specific antibody against UreB in sera of H pylori infectedpatients indicate that UreB is an excellent antigen candidate for developing H pylori vaccine.
Authors: J F Tomb; O White; A R Kerlavage; R A Clayton; G G Sutton; R D Fleischmann; K A Ketchum; H P Klenk; S Gill; B A Dougherty; K Nelson; J Quackenbush; L Zhou; E F Kirkness; S Peterson; B Loftus; D Richardson; R Dodson; H G Khalak; A Glodek; K McKenney; L M Fitzegerald; N Lee; M D Adams; E K Hickey; D E Berg; J D Gocayne; T R Utterback; J D Peterson; J M Kelley; M D Cotton; J M Weidman; C Fujii; C Bowman; L Watthey; E Wallin; W S Hayes; M Borodovsky; P D Karp; H O Smith; C M Fraser; J C Venter Journal: Nature Date: 1997-08-07 Impact factor: 49.962
Authors: Brian J McMahon; Thomas W Hennessy; J Michael Bensler; Dana L Bruden; Alan J Parkinson; Julie M Morris; Alisa L Reasonover; Debby A Hurlburt; Michael G Bruce; Frank Sacco; Jay C Butler Journal: Ann Intern Med Date: 2003-09-16 Impact factor: 25.391