A proteomic approach for the identification of bismuth-binding proteins in Helicobacter pylori

Abstract

Helicobacter pylori is a major human pathogen that can cause peptic ulcers and chronic gastritis. Bismuth-based triple or quadruple therapies are commonly recommended for the treatment of H. pylori infections. However, the molecular mechanisms underlying treatment with bismuth are currently not fully understood. We have conducted a detailed comparative proteomic analysis of H. pylori cells both before and after treatment with colloidal bismuth subcitrate (CBS). Eight proteins were found to be significantly upregulated or downregulated in the presence of CBS (20 microg mL(-1)). Bismuth-induced oxidative stress was confirmed by detecting higher levels of lipid hydroperoxide (approximately 1.8 times) and hemin (approximately 3.4 times), in whole cell extracts of bismuth-treated H. pylori cells, compared with those from untreated cells. The presence of bismuth also led to an approximately eightfold decrease in cellular protease activities. Using immobilized-bismuth affinity chromatography, we isolated and subsequently identified seven bismuth-binding proteins from H. pylori cell extracts. The intracellular levels of four of these proteins (HspA, HspB, NapA and TsaA) were influenced by the addition of CBS, which strongly suggests that they interact directly with bismuth. The other bismuth-interacting proteins identified were two enzymes (fumarase and the urease subunit UreB), and a translational factor (Ef-Tu). Our data suggest that the inhibition of proteases, modulation of cellular oxidative stress and interference with nickel homeostasis may be key processes underlying the molecular mechanism of bismuth's actions against H. pylori.

Antigenic Proteins of Helicobacter pylori of Potential Diagnostic Value

“…The sample was focused with a maximum current of 50 μA, a maximum power of 200 mW and typical voltages ranging from 400 to 4000 V until 64 kVh was reached, after approximately 17 hrs (Baik et al, 2004;Ge et al, 2007). For the second dimension, samples from each of the 12 OFF-GEL fractions were separately mixed with sample buffer (4:1 ratio) containing 28.6% SDS and 4.76% 2-mercaptoethanol.…”

A Histidine-rich and Cysteine-rich Metal-binding Domain at the C Terminus of Heat Shock Protein A from Helicobacter pylori

“…A number of proteins and enzymes have been demonstrated previously as intracellular targets of bismuth (20). Using a metalloproteomic approach, it was found that intracellular levels of four proteins (HspA, HspB, NapA, and TsaA) were significantly up-or down-regulated after bismuth treatment (21), and thus bismuth-binding proteins in H. pylori were identified. Moreover, HspA was found to be one of the Bi 3ϩ -binding proteins by immobilized bismuth affinity chromatography.…”

Metallomics: Guidelines for terminology and critical evaluation of analytical chemistry approaches (IUPAC Technical Report)

“…The IMAC approach enjoys a growing popularity with recent applications referring to the analysis of the zinc [56,57] and copper [56][57][58] proteomes in human hepatoma cell lines, uranyl proteome in human serum [59], bismuth proteome in Helicobacter pylori cell extracts [60], and Ni-proteome in human keratinocytes [61,62] and Arabidopsis thaliana roots [63].…”