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Oxidative stress triggers thiol oxidation in the glyceraldehyde‐3‐phosphate dehydrogenase of Staphylococcus aureus
Author(s) -
Weber Harald,
Engelmann Susanne,
Becher Dörte,
Hecker Michael
Publication year - 2004
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2004.03971.x
Subject(s) - dehydrogenase , biochemistry , glyceraldehyde 3 phosphate dehydrogenase , biology , enzyme , staphylococcus aureus , oxidative stress , isoelectric point , oxidative phosphorylation , glyceraldehyde , bacteria , genetics
Summary The high‐resolution two‐dimensional protein gel electrophoresis technique combined with matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) was used to analyse the oxidative stress response in Staphylococcus aureus COL. Exponentially growing cells were supplemented with 100 mM H 2 O 2 leading to a growth arrest lasting 30 min. The comparison of the two‐dimensional pattern of cytoplasmic protein extracts of stressed and unstressed cells revealed only a few changes in the protein synthesis profile. However, the isoelectric points of Gap (glyceraldehyde‐3‐phosphate dehydrogenase), AhpC (alkylhydroperoxide reductase) and MvaS (HMG‐CoA‐synthase) changed strikingly. For analysis of the modification of Gap, tandem hybrid mass spectrometry (Q‐Star) was used. The observed pI shift resulted from the oxidation to sulphonic acid of cysteine 151, which is crucial for catalytic activity. A drop in ATP and a complete inactivation of Gap was accompanied by the growth arrest. About 30 min after the addition of H 2 O 2 , the damaged Gap was still present, but a new protein spot at the original location became visible, representing the newly synthesized enzyme that is active again. This is accompanied by the restoration of Gap enzyme activity, ATP levels and recovery of growth. There is a strong correlation between growth, ATP level and Gap activity under oxidative stress conditions, indicating that the H 2 O 2 ‐triggered Gap inactivation might be one reason for growth arrest under these conditions. Our data indicate that the damaged Gap protein was not repaired.