Reaction Mechanism of Human Glutathione Reductase
NADPH reduces FAD present in GSR to produce a transient FADH- anion. This anion then quickly breaks a disulfide bond (Cys58 - Cys63) and leads to Cys63's nucleophilically attacking the nearest sulfide unit in the GSSG molecule (promoted by His467), which creates a mixed disulfide bond (GS-Cys58) and a GS- anion. His467 of GSR then protonates the GS- anion to form the first GSH. Next, Cys63 nucleophilically attacks the sulfide of Cys58, releasing a GS- anion, which, in turn, picks up a solvent proton and is released from the enzyme, thereby creating the second GSH. So, for every GSSG and NADPH, two reduced GSH molecules are gained, which can again act as antioxidants scavenging reactive oxygen species in the cell.
Read more about this topic: Glutathione Reductase
Famous quotes containing the words reaction, mechanism and/or human:
“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)
“When one of us dies of cancer, loses her mind, or commits suicide, we must not blame her for her inability to survive an ongoing political mechanism bent on the destruction of that human being. Sanity remains defined simply by the ability to cope with insane conditions.”
—Ana Castillo (b. 1953)
““More human than human” is our motto.”
—David Webb Peoples, U.S. screenwriter, and Ridley Scott. Tyrell (Joe Turkel)