In vitro inhibition of topoisomerase IIα by reduced glutathione

Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
Acta biochimica Polonica (Impact Factor: 1.15). 01/2011; 58(2):265-7.
Source: PubMed


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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    • "In healthy cells and tissues, over 90% of total glutathione is in reduced form GSH and less than 10% in disulphide form GSSG (Griffith 1999). An increase in the proportion of GSSG to GSH is considered to indicate oxidative stress (Martínez Sarrasague et al. 2006; Valko et al. 2007; Badjatia et al. 2010; Delwar et al. 2011). "
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