Brief Reports
Copyright ©2005 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jan 21, 2005; 11(3): 454-456
Published online Jan 21, 2005. doi: 10.3748/wjg.v11.i3.454
Fusion expression of Helicobacter pylori neutrophil-activating protein in E.coli
Qiao-Zhen Kang, Guang-Cai Duan, Qing-Tang Fan, Yuan-Lin Xi
Qiao-Zhen Kang, Department of Bioengineering, Zhengzhou University, Zhengzhou 450052, Henan Province, China
Guang-Cai Duan, Qing-Tang Fan, Henan Key Laboratory of Molecular Medicine, Zhengzhou University, Zhengzhou 450052, Henan Province, China
Yuan-Lin Xi, College of Public Health, Zhengzhou University, Zhengzhou 450052, Henan Province, China
Author contributions: All authors contributed equally to the work.
Supported by the Medical Science Foundation for Distinguished Scholars of Henan Province, No. 200084
Correspondence to: Dr. Guang-Cai Duan, Henan Key Laboratory of Molecular Medicine, Zhengzhou University, Zhengzhou 450052, Henan Province, China. gcduan@public2.zz.ha.cn
Telephone: +86-371-6912869
Received: March 3, 2004
Revised: March 7, 2004
Accepted: April 13, 2004
Published online: January 21, 2005
Abstract

AIM: To produce a recombinant protein rMBP-NAP, which was fusionally expressed by Helicobacter pylori (H pylori) neutrophil-activating protein (NAP) and E. coli maltose-binding protein (MBP) and to evaluate its immunoreactivity and immunogenicity.

METHODS: Neutrophil-activating protein gene of H pylori (HP-napA) was subcloned from the recombinant plasmid pNEB-napA, and fused to MalE gene of expressing vector pMAL-c2x. The recombinant plasmid pMAL-c2x-napA was confirmed by restriction enzyme digestion, and then transformed into E. coli TB1. Fusion protein rMBP-NAP was induced by IPTG and identified by SDS-PAGE analysis. Soluble rMBP-NAP was purified by amylose affinity chromatography. Immunoreactivity and immunogenicity of the fusion protein were evaluated by animal experiment, Western blotting with human H pylori anti-sera.

RESULTS: E.coli TB1 carrying recombinant plasmid pMAL-c2x-napA was constructed and led to a high efficiency cytosol expression of fusion protein rBMP -NAP when induced by IPTG. The molecular weight of rBMP-NAP was about 57 kD, accounting for 37.55% of the total protein in the sonicated supernatant of E. coli TB1 (pMAL-c2x-napA). The purity of the fusion protein after one-step affinity chromatography was 94% and the yield was 100 mg per liter of bacterial culture. The purified fusion protein could be specifically recognized by both human anti-sera from clinical patients with H pylori infection and rabbit sera immunized by rMBP-NAP itself.

CONCLUSION: Recombinant protein rMBP-NAP might be a novel antigen for vaccine development against H pylori.

Keywords: Helicobacter pylori; Neutrophil-activating protein; Maltose-binding protein; E.coli