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In vitro inhibition of topoisomerase IIα by reduced glutathione.

Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
Acta biochimica Polonica (Impact Factor: 1.19). 01/2011; 58(2):265-7.
Source: PubMed

ABSTRACT In most cells, the major intracellular redox buffer is glutathione (GSH) and its disulfide-oxidized (GSSG) form. The GSH/GSSG system maintains the intracellular redox balance and the essential thiol status of proteins by thiol disulfide exchange. Topoisomerases are thiol proteins and are a target of thiol-reactive substances. In this study, the inhibitory effect of physiological concentration of GSH and GSSG on topoisomerase IIα activity in vitro was investigated. GSH (0-10 mM) inhibited topoisomerase IIα in a concentration-dependent manner while GSSG (1-100 µM) had no significant effect. These findings suggest that the GSH/GSSG system could have a potential in vivo role in regulating topoisomerase IIα activity.

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