İnhibition of brain glutathione reductase by sodium arsenite

Year 1994, Volume: 7 Issue: 3, 115 - 118, 01.08.1994

N.l. Açan E.f. Tezcan

Abstract

The aim of this study is to investigate the inhibition characteristics of brain glutathione reductase (GSSGR) under reducing conditions. Sheep brain glutathione reductase (GSSGR, NAD(P)H: oxidized glutathione oxidoreductase, EC 1.6.4.2) was purified about 1 1000 fold with a method employing ammonium sulphate fractionation, heat denaturation, 2',5‘-ADP Sepharose 4B and Sepharose C16B chromatography steps. NADPH is an inhibitor of brain GSSGR. Sodium arsenite, which is a specific inhibitor of enzymes having two nascent -SH groups, had little inhibitory effect on GSSGR when incubated with the enzyme alone. When the enzyme was incubated with both NADPH and arsenite, inhibition was intensified.

2-Mercaptoethanol and reduced glutathione enhanced the inhibition further; whereas oxidized glutathione protected the enzyme from inhibition. The reaction mechanism of the enzyme is discussed in the light of these findings.

Keywords

Glutathione reductase, sheep brain, inhibition, NADPH, sodium arsenite, thiol reagents

References

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