Glutathione reductase（GSR) belongs to the class-I pyridine nucleotide-disulfide oxidoreductase family. The GSR enzyme is a homodimeric flavoprotein and has a role in maintaining glutathione（GSH) in its reduced form by catalyzing the reduction of glutathione disulfide（GSSG): GSSG + NADPH + H+ ->2GSH + NADP+. In the majority of eukaryotic cells， GSR upholds the ratio of [GSH] / [GSSG]， and partakes in quite a few critical functions such as the detoxification of reactive oxygen species as well as protein and DNA biosynthesis.
