Induction of manganese-superoxide dismutase by membrane-binding drugs in Escherichia coli.
AUTOR(ES)
Zhang, Q M
RESUMO
Treatment of exponentially growing cells of Escherichia coli with membrane-binding drugs such as chlorpromazine (CPZ) and procaine resulted in an induction of manganese-superoxide dismutase (Mn-SOD). A slight decrease was observed in the amount of Fe-SOD. The induction of Mn-SOD required de novo synthesis of this enzyme, since it was suppressed by rifampin. The treatment did not cause the induction of Mn-SOD when performed under anaerobic conditions. In E. coli cells with a sodA-lacZ operon fusion, CPZ and procaine induced beta-galactosidase in the presence of oxygen, whereas it was not expressed and was not induced by CPZ and procaine under anaerobic conditions. Although CPZ reduced the ability of cell suspensions to take up oxygen, it increased the cyanide-resistant fraction of the total respiration. Therefore, it appeared likely that the induction of the sodA gene was a response to an increase in superoxide radical production mediated by these membrane-binding drugs in E. coli cells, possibly by disruption of the electron transport systems in the cell membranes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=207962Documentos Relacionados
- A yeast mutant lacking mitochondrial manganese-superoxide dismutase is hypersensitive to oxygen.
- Paraquat-mediated selection for mutations in the manganese-superoxide dismutase gene sodA.
- Differential Accumulation of Manganese-Superoxide Dismutase Transcripts in Maize in Response to Abscisic Acid and High Osmoticum.
- GTPase-dependent signaling in bacteria: characterization of a membrane-binding site for era in Escherichia coli.
- Cloning and sequencing analysis of a complementary DNA for manganese-superoxide dismutase from rice (Oryza sativa L.).