The reduction of serum albumin, insulin and some simple disulphides by glutathione.

It was suggested by Hopkins & Morgan (1938) that glutathione (GSH) may function as a reducing agent maintaining certain enzymes in the reduced and active state, and it is usual to add glutathione, cysteine or some other thiol compound to systems depending on thiol groups for their activity. However, a considerable excess is added and the reduction of the disulphide bonds is not enzymic. In connexion with the above suggested biological function of GSH, there has been little work done on the enzymic reduction of disulphide bonds of oxidized enzymes by catalytic amounts of GSH in the presence of glutathione reductase and reduced nicotinamide-adenine dinucleotides (NADH2 and NADPH2). Such a system has, however, been used by HiAlsmann & Lipmann (1960) to maintain