Hydrogen peroxide induces protection against lethal effects of cumene hydroperoxide in Escherichia coli cells: an Ahp dependent and OxyR independent system?
Pretreatment with 2.5 mM H2O2 protects bacterial cells against cumene hydroperoxide killing. This response is independent of the OxyR system, but possibly involves the participation of Ahp protein, since ahp mutants are not protected. Treatment of bacterial cells with high H2O2 concentrations caused an alteration on the electrophoretic profile of the smaller subunit (22-kDa) of Ahp. This alteration does not require novel gene products and is not dependent on the OxyR protein. In this way, we propose that the modification of the 22-kDa subunit of Ahp by high H2O2 concentration may be responsible for the protection against the lethal effects of cumene hydroperoxide.
Asad
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Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Brazil. nasser@uerj.br
Asad
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Silva
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Felzenszwalb
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Leitão
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D001426:Bacterial Proteins / Q000502:physiology; D001555:Benzene Derivatives / Q000633:toxicity*; D004268:DNA-Binding Proteins; D004336:Drug Antagonism; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology*; D029968:Escherichia coli Proteins; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016877:Oxidants / Q000633:toxicity*; D010088:Oxidoreductases / Q000502:physiology*; D010544:Peroxidases; D054464:Peroxiredoxins; D012097:Repressor Proteins / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*
D001426:Bacterial Proteins; D001555:Benzene Derivatives; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D016877:Oxidants; D012097:Repressor Proteins; D014157:Transcription Factors; C499299:oxyR protein, E coli; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D010544:Peroxidases; D054464:Peroxiredoxins; C007164:cumene hydroperoxide