Reaction
The main reaction that glutathione peroxidase catalyzes is:
- 2GSH + H2O2 → GS–SG + 2H2O
where GSH represents reduced monomeric glutathione, and GS–SG represents glutathione disulfide. The mechanism involves oxidation of the selenol of a selenocysteine residue by hydrogen peroxide. This process gives the derivative with a selenenic acid (RSeOH) group. The selenenic acid is then converted back to the selenol by a two step process that begins with reaction with GSH to form the GS-SeR and water. A second GSH molecule reduces the GS-SeR intermediate back to the selenol, releasing GS-SG as the by-product. A simplified representation is shown below:
- RSeH + H2O2 → RSeOH + H2O
- RSeOH + GSH → GS-SeR + H2O
- GS-SeR + GSH → GS-SG + RSeH
Glutathione reductase then reduces the oxidized glutathione to complete the cycle:
- GS–SG + NADPH + H+ → 2 GSH + NADP+.
Read more about this topic: Glutathione Peroxidase
Famous quotes containing the word reaction:
“In a land which is fully settled, most men must accept their local environment or try to change it by political means; only the exceptionally gifted or adventurous can leave to seek his fortune elsewhere. In America, on the other hand, to move on and make a fresh start somewhere else is still the normal reaction to dissatisfaction and failure.”
—W.H. (Wystan Hugh)
“Children, randomly at first, hit upon something sooner or later that is their mother’s and/or father’s Achilles’ heel, a kind of behavior that especially upsets, offends, irritates or embarrasses them. One parent dislikes name-calling, another teasing...another bathroom jokes. For the parents, this behavior my have ties back to their childhood, many have been something not allowed, forbidden, and when it appears in the child, it causes high-voltage reaction in the parent.”
—Ellen Galinsky (20th century)
“Christianity was only a very strong and singularly well-timed Salvation Army movement that happened to receive help from an unusual and highly dramatic incident. It was a Puritan reaction in an age when, no doubt, a Puritan reaction was much wanted; but like all sudden violent reactions, it soon wanted reacting against.”
—Samuel Butler (1835–1902)