title: [Cloning, expression and identification of catalase of Helicobacter pylori].
abstract: OBJECTIVE
  To construct the recombinant plasmid containing catalase (KatA) of Helicobacter pylori (Hp), analyze its nucleic acid sequence, express it in E. coli and study its antigenicity.
  
  
  METHODS
  KatA fragments were amplified from Hp chromosomal DNA by PCR. Its T-A was cloned, sequenced and compared with other HP strains on the GenBank. Then the gene cloned into pGEX-4T-1 fusion expression vector was expressed in E. coli and purified by GST-affinity chromatography. The purified product was used to identify 29 stains of mouse anti Hp monoclonal antibodies and analyze antigenicity with serum of Hp-infected patients by Western blot.
  
  
  RESULTS
  KatA fragments were composed of 1,515 bp (GenBank No. DQ333889) and the nucleotide homology with other Hp strains on the GenBank was 96%-97%. 85 kDa of the recombinant KatA-pGEX-4T-1 was expressed in E. coli. 4 of 29 anti-Hp mouse monoclonal antibodies were against KatA. Western blot analysis proved that KatA was specifically recognized in the serum of Hp-infected patients.
  
  
  CONCLUSIONS
  The recombinant KatA has original antigenicity. It is of great value to clinical sero-diagnosis and vaccine study of Hp.
authors.affiliation: Department of Tropical Diseases, School of Biotechnology, Southern Medical University, Guangzhou 510515, China. lyinf@163.com
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Yun-shan
authors.initials: YS
authors.lastname: Ning
authors.forename: Min
authors.initials: M
authors.lastname: Long
authors.forename: Wen-qi
authors.initials: WQ
authors.lastname: Dong
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis / Q000276:immunology; D002374:Catalase / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D016481:Helicobacter Infections / Q000097:blood / Q000276:immunology; D016480:Helicobacter pylori / Q000201:enzymology*; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D000911:Antibodies, Monoclonal; D002374:Catalase; D004262:DNA Restriction Enzymes