Purification and relationship with gastric disease of a 130 kDa (CagA) protein of Helicobacter pylori.
OBJECTIVE
The aims of this research were to purify and identify the 130 kDa (CagA) protein of H. pylori clinical isolate HP97002 and evaluate the relationships between the purified 130 kDa (CagA) protein and gastric diseases.


METHODS
The procedure for isolating the protein included 6 mol/L guanidine extract, size exclusion chromatography and elusion from gel. Sera of 68 patients with gastric diseases (44 with chronic gastritis, 15 with atrophic gastritis, 7 with peptic ulcer disease, 2 with gastric cancer) were obtained, and the serological response to CagA was studied by Western-blot using the purified protein.


RESULTS
The purified protein was 130 kDa and preserved good antigenicity and revealed basic isoelectric point about of 8.1. Among 68 sera, 43 sera could recognize the purified protein associated with chronic gastritis 47.7% (21/44), atrophic gastritis 86.7% (13/15), peptic ulcer disease 100% (77), gastric cancer 100% (2/2). Compared with each other, the difference was significant (chi2 = 13.327, P = 0.004), and 130 kDa (CagA) protein was associated with severe gastric diseases ( r(S) = 0.442, P = 0.001).


CONCLUSIONS
The 130 kDa (CagA) protein was associated with severe gastric diseases.
Ye
Shao-Jing
SJ
Department of Microbiology, College of Medicine, Zhejiang University, Hangzhou 310006, China. yesj@zju.edu.cn
Fang
Ping-Chu
PC
Mao
Guo-Gen
GG
Li
Chao-Long
CL
Qiu
Xiang
X
Chen
Hai-Xiang
HX
D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification*; D002478:Cells, Cultured; D002908:Chronic Disease; D005756:Gastritis / Q000276:immunology; D016481:Helicobacter Infections / Q000378:metabolism / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D010437:Peptic Ulcer / Q000382:microbiology*; D012016:Reference Values; D013045:Species Specificity; D013272:Stomach Diseases / Q000382:microbiology*; D013274:Stomach Neoplasms / Q000382:microbiology
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori