# Regulation of the activity of glyceraldehyde 3-phosphate dehydrogenase by glutathione and $H_2O_2$

Vaidyanathan, VV and Sastry, PS and Ramasarma, T (1993) Regulation of the activity of glyceraldehyde 3-phosphate dehydrogenase by glutathione and $H_2O_2$. In: Molecular and Cellular Biochemistry, 129 (1). pp. 57-65.

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## Abstract

The activity lost during storage of a solution of muscle glyceraldehyde 3-phosphate dehydrogenase was rapidly restored on adding a thiol, but not arsenite or azide. On treatment with $H_2O_2$, the enzyme was partially inactivated and complete loss of activity occurred in the presence of glutathione. Samples of the enzyme pretreated with glutathione followed by removal of the thiol by filtration on a Sephadex column showed both full activity and its complete loss on adding $H_2O_2$, in the absence of added glutathione. Most of the activity was restored when the $H_2O_2$-inactivated enzyme was incubated with glutathione (25 mM) or dithiothreitol (5 mM), whereas arsenite or azide were partially effective and ascorbate was ineffective. The need for incubation for a long time with a strong reducing agent for restoration of activity suggested that the oxidized group (disulfide or sulfenate) must be in a masked state in the $H_2O_2$-inactivated enzyme. Analysis by SDS-PAGE gave evidence for the formation of a small quantity of glutathione-reversible disulfide-form of the enzyme. CD spectra indicated a decrease in $\alpha$-helical content in the activated form of the enzyme. The evidence suggested that glutathione and $H_2O_2$ could regulate the active state of this enzyme.

Item Type: Journal Article Copyright of this article belongs to Springer. glyceraldehyde-3-P dehydrogenase;H2O2-inactivation;thiol requirement;structural/redox role of GSH Division of Biological Sciences > Biochemistry 01 Jul 2008 19 Sep 2010 04:46 http://eprints.iisc.ernet.in/id/eprint/14629