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Proteomic analysis of antioxidant strategies of Staphylococcus aureus : Diverse responses to different oxidants
Author(s) -
Wolf Carmen,
Hochgräfe Falko,
Kusch Harald,
Albrecht Dirk,
Hecker Michael,
Engelmann Susanne
Publication year - 2008
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200701062
Subject(s) - hydrogen peroxide , chemistry , biochemistry , paraquat , oxidative stress , antioxidant , enzyme , thiol , reactive oxygen species , staphylococcus aureus , oxidative phosphorylation , superoxide , protein carbonylation , glutathione , bacteria , biology , genetics
The high resolution 2‐D protein gel electrophoresis technique combined with MALDI‐TOF MS and a recently developed fluorescence‐based thiol modification assay were used to investigate the cellular response of Staphylococcus aureus to oxidative stress. Addition of hydrogen peroxide, diamide, and the superoxide generating agent paraquat to exponentially growing cells revealed complex changes in the protein expression pattern. In particular, proteins involved in detoxification, repair systems, and intermediary metabolism were found to be up‐regulated. Interestingly, there is only a small overlap of proteins induced by all these stressors. Exposure to hydrogen peroxide mediated a significant increase of DNA repair enzymes, whereas treatment with diamide affected proteins involved in protein repair and degradation. The activity of proteins under oxidative stress conditions can be modulated by oxidation of thiol groups. In growing cells, protein thiols were found to be mainly present in the reduced state. Diamide mediated a strong increase of reversibly oxidized thiols in a variety of metabolic enzymes. By contrast, hydrogen peroxide resulted in the reversible oxidation especially of proteins with active site cysteines. Moreover, high levels of hydrogen peroxide influenced the p I of three proteins containing cysteines within their active sites (GapA1, AhpC, and HchA) indicating the generation of sulfinic or sulfonic acid by irreversible oxidation of thiols.