Tandoğan Berivan, Ulusu N Nuray
Hacettepe University, Faculty of Medicine, Department of Biochemistry, 06100 Ankara, Turkey.
J Enzyme Inhib Med Chem. 2007 Aug;22(4):489-95. doi: 10.1080/14756360601162147.
Glutathione reductase (GR, type IV, Baker's yeast, E.C 1.6.4.2) is a flavoprotein that catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH). In this study some metal ions have been tested on GR; lithium, manganese, molybdate, aluminium, barium, zinc, calcium, cadmium and nickel. Cadmium, nickel and calcium showed a good to moderate inhibitory effect on yeast GR. GR is inhibited non-competitively by Zn2+ (up to 2 mM) and activated above this concentration. Ca2+ inhibition was non-competitive with respect to GSSG and uncompetitive with respect to NADPH. Nickel inhibition was competitive with respect to GSSG and uncompetitive with respect to NADPH. The inhibition constants for these metals on GR were determined. The chelating agent EDTA recovered 90% of the GR activity inhibited by these metals.
谷胱甘肽还原酶（GR，IV型，面包酵母，E.C 1.6.4.2）是一种黄素蛋白，催化依赖NADPH将氧化型谷胱甘肽（GSSG）还原为还原型谷胱甘肽（GSH）。在本研究中，对GR测试了一些金属离子；锂、锰、钼酸盐、铝、钡、锌、钙、镉和镍。镉、镍和钙对酵母GR表现出良好到中等程度的抑制作用。Zn2+（高达2 mM）对GR有非竞争性抑制作用，高于此浓度则有激活作用。Ca2+对GSSG的抑制是非竞争性的，对NADPH的抑制是反竞争性的。镍对GSSG的抑制是竞争性的，对NADPH的抑制是反竞争性的。测定了这些金属对GR的抑制常数。螯合剂EDTA恢复了被这些金属抑制的90%的GR活性。
