Proteomic analysis of Helicobacter pylori cellular proteins fractionated by ammonium sulfate precipitation
Related Experiment Video
Updated: Jul 4, 2026
Separation and Fractionation of Cell Wall and Cell Membrane Proteins from Mycobacterium tuberculosis for Downstream Protein Analysis
Published on: September 26, 2025
Jeong-Won Park1, Seung-Gyu Lee, Jae-Young Song
1Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.
Abstract:
Among 1590 ORFs in the Helicobacter pylori genome, >250 have been identified as authentic genes by proteomic analysis. Low-abundance proteins need to be enriched to a minimal amount for MALDI-TOF analysis and salt precipitation has generally been used for protein enrichment. Here, a whole-cell extract of H. pylori strain 26695 was subjected to protein fractionation with stepwise concentrations of ammonium sulfate and the proteins were displayed by 2-DE. The protein spots were quantified using PDQUEST software and identified by peptide fingerprinting. The 2-DE profiles and intensities of individual protein spots differed among the protein fractions. Out of the 98 identified proteins, 61 were found in the stepwise ammonium sulfate fractions but not in the whole-cell extract. Out of these, 37 proteins, including KdsA, were found exclusively in a single fraction. In contrast, GroEL, UreA, UreB, TrxA, NapA, and FldA were ubiquitously present in all fractions. Iron-containing proteins such as NapA, SodB, CeuE, and Pfr were found predominantly in the 100% saturated ammonium sulfate precipitate. Additionally, 29 proteins were newly identified in this study. These data will facilitate the preparation of significant H. pylori proteins, as well as provide information about low-abundance proteins.
Insights
This study optimized protein enrichment for Helicobacter pylori using ammonium sulfate fractionation, identifying 61 new proteins, including 37 unique ones. This method aids in discovering low-abundance proteins for further research.
Area of Science:
- Microbiology
- Proteomics
- Biochemistry
Background:
- Helicobacter pylori has over 1590 open reading frames (ORFs), with >250 identified genes via proteomics.
- Low-abundance protein identification requires enrichment, commonly achieved through salt precipitation for MALDI-TOF analysis.
Purpose of the Study:
- To develop an optimized protein fractionation method for H. pylori using stepwise ammonium sulfate precipitation.
- To identify low-abundance and novel proteins within H. pylori strain 26695.
Main Methods:
- Whole-cell extract of H. pylori strain 26695 was fractionated using stepwise ammonium sulfate concentrations.
- Proteins were separated using 2-dimensional electrophoresis (2-DE) and quantified with PDQUEST software.
- Peptide fingerprinting was employed for protein identification.
Main Results:
- Differential protein profiles and spot intensities were observed across ammonium sulfate fractions.
- 61 of 98 identified proteins were exclusively found in the fractions, not the whole-cell extract.
- 37 proteins, including KdsA, were uniquely identified in single fractions, while 29 proteins were newly discovered.
Conclusions:
- Stepwise ammonium sulfate fractionation effectively enriches for specific H. pylori proteins, including low-abundance ones.
- This method enhances the identification of novel proteins and facilitates the preparation of significant H. pylori proteins.
- The study provides valuable insights into the H. pylori proteome and aids in the discovery of previously unidentified proteins.
