Proteome analysis of a catalase-deficient isogenic mutant of Helicobacter pylori 26695

Abstract

Helicobacter pylori, a gram-negative bacterium, is a causative agent of gastroduodenal diseases of human. Human immune system produces harmful reactive oxygen species to kill this bacterium that locates the microaerophilic mucous layer. H. pylori harbors various antioxidant enzymes including SodB, KatA and AhpC to protect the oxygen toxicity. We removed the catalase gene (katA) from H. pylori 26695 genome, and the change of profile of the gene expression of the mutant was analyzed by high resolution 2-DE followed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), tandem MS and microarray analysis. Eleven and 37 genes were upregulated and downregulated in the mutant respectively, either transcriptionally or translationally. Expression level of pfr and hp1588 that were decreased on protein level in the mutant was confirmed by RT-PCR analysis.