Glutathione reductase (GR) also known as glutathione-disulfide reductase (GSR) is an enzyme that in humans is encoded by the GSR gene. Glutathione reductase (EC 1.8.1.7) catalyzes the reduction of glutathione disulfide (GSSG) to the sulfhydryl form glutathione (GSH), which is a critical molecule in resisting oxidative stress and maintaining the reducing environment of the cell.[5][6][7] Glutathione reductase functions as dimeric disulfide oxidoreductase and utilizes an FADprosthetic group and NADPH to reduce one molar equivalent of GSSG to two molar equivalents of GSH:
The glutathione reductase is conserved between all kingdoms. In bacteria, yeasts, and animals, one glutathione reductase gene is found; however, in plant genomes, two GR genes are encoded. Drosophila and trypanosomes do not have any GR at all.[8] In these organisms, glutathione reduction is performed by either the thioredoxin or the trypanothione system, respectively.[8][9]
^Mannervik B (August 1987). "The enzymes of glutathione metabolism: an overview". Biochem. Soc. Trans. 15 (4): 717–8. doi:10.1042/bst0150717. PMID3315772.
^ abKanzok SM, Fechner A, Bauer H, Ulschmid JK, Müller HM, Botella-Munoz J, Schneuwly S, Schirmer R, Becker K (2001). "Substitution of the thioredoxin system for glutathione reductase in Drosophila melanogaster". Science. 291 (5504): 643–6. Bibcode:2001Sci...291..643K. doi:10.1126/science.291.5504.643. PMID11158675.
^Krauth-Siegel RL, Comini MA (2008). "Redox control in trypanosomatids, parasitic protozoa with trypanothione-based thiol metabolism". Biochim Biophys Acta. 1780 (11): 1236–48. doi:10.1016/j.bbagen.2008.03.006. PMID18395526.