Glutathione reductase from bakers' yeast and beef liver.

The reduction of glutathione by a heat-labile system in liver was discovered by Hopkins and Elliott (1). Later Mann (2) obtained a soluble enzyme preparation from liver which required, for the reduction process, a cofactor and glucose as hydrogen donor. Meldrum and Tarr (3) found that oxidized glutathione was reduced by rat blood and by yeast and demonstrated the function of TPNl as a cofactor in this system. Hexose monophosphate was used as a hydrogen donor for the reduction of TPN. More recently Conn and Vennesland (4), Mapson and Goddard (5), and Rall and Lehninger (6) demonstrated the presence of glutathione reductase in wheat germ, pea seeds, and liver and showed that, in all instances, TPN was an obligatory cofactor and that DPN was inactive. In the present communication the preparation of glutathione reductase from yeast and the partial purification of this enzyme from beef liver are reported. Under suitable conditions both enzyme preparations were found to be active with DPN as well as TPN as the coenzyme. The reaction with reduced DPN is considerably slower than that with reduced TPN; it is stimulated by phosphate and inhibited by some other ions.