GPx catalyzes the reduction of peroxides, using reduced glutathione (GSH) as a co-substrate. The general reaction can be summarized as follows: 2 GSH + H2O2 → GSSG + 2 H2O In this reaction, two molecules of GSH are oxidized to form one molecule of glutathione disulfide (GSSG) and two molecules of water. GPx has several isoforms, each with specific tissue distributions and substrate specificities, which allows it to offer a broad spectrum of protection against oxidative damage.
