Original Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Feb 7, 2011; 17(5): 618-624
Published online Feb 7, 2011. doi: 10.3748/wjg.v17.i5.618
Analysis of the urinary peptidome associated with Helicobacter pylori infection
Di Xiao, Fan-Liang Meng, Li-Hua He, Yi-Xin Gu, Jian-Zhong Zhang
Di Xiao, Fan-Liang Meng, Li-Hua He, Yi-Xin Gu, Jian-Zhong Zhang, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Author contributions: Zhang JZ and Xiao D designed the study, acquired the data and drafted the manuscript; Meng FL, He LH and Gu YX recruited volunteers, collected and analyzed urine samples, and performed 13C-urea breath test; all authors read and approved the final manuscript.
Supported by The National Science and Technology Pillar Program of the Ministry of Science and Technology of the People’s Republic of China during the Eleventh Five-Year plan period, No. 2007BAID4B02
Correspondence to: Jian-Zhong Zhang, Professor, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, PO Box 5, Changping District, Beijing 102206, China. zhangjianzhong@icdc.cn
Telephone: +86-10-58900754 Fax: +86-10-58900707
Received: August 14, 2010
Revised: September 29, 2010
Accepted: October 6, 2010
Published online: February 7, 2011
Abstract

AIM: To investigate the relationship between urinary peptide changes and Helicobacter pylori (H. pylori) infection using urinary peptidome profiling.

METHODS: The study was performed in volunteers (n = 137) who gave informed consent. Urinary peptides were enriched by magnetic beads based weak cation exchange chromatography and spectrums acquired by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). ClinProTools bioinformatics software was used for statistical analysis and the recognition of peptide patterns. The marker peptides were identified by LTQ Obitrap XL tandem MS.

RESULTS: Approximately 50 proteins or peptides which loaded onto the magnetic beads were detected by MALDI-TOF MS. By optimizing the parameters of the model, the Genetic Algorithm model had good recognition capability (97%) and positive predictive value (94%). Based on the model, 2 markers with molecular masses of 6788 and 1912 Da were found that differentiated between H. pylori positive and negative volunteers. The m/z 1912 sequence was parsed as SKQFTSSTSYNRGDSTF. The peptide was identified as isoform 1 of the fibrinogen α chain precursor, whose concentration in urine was markedly higher in H. pylori infected volunteers than in H. pylori non-infected ones.

CONCLUSION: The appearance of urinary fibrinogen degradation products is caused by an active H. pylori-induced process.

Keywords: Urinary peptidome profiling; MB-matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; Helicobacter pylori; Fibrinogen degradation products