Search results
Results from the WOW.Com Content Network
After the final GSH product is made, it can be used by glutathione peroxidase to neutralize reactive oxygen species (ROS) such as H 2 O 2 or Glutathione S-transferases in the detoxification of xenobiotics. [7] Reaction mechanism for GSH biosynthesis. [14] Glutamate and cysteine side chains are shown in red and green, respectively.
Glutathione (GSH, / ˌ ɡ l uː t ə ˈ θ aɪ oʊ n /) is an organic compound with the chemical formula HOCOCH(NH 2)CH 2 CH 2 CONHCH(CH 2 SH)CONHCH 2 COOH. It is an antioxidant in plants , animals , fungi , and some bacteria and archaea .
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: [5] RSeH + H 2 O 2 → RSeOH + H 2 O RSeOH + GSH → GS-SeR + H 2 O GS-SeR + GSH → GS-SG + RSeH. Glutathione reductase then reduces the oxidized glutathione to complete the cycle:
Glutamate–cysteine ligase (GCL) EC 6.3.2.2), previously known as γ-glutamylcysteine synthetase (GCS), is the first enzyme of the cellular glutathione (GSH) biosynthetic pathway that catalyzes the chemical reaction:
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 to the sulfhydryl form glutathione (), which is a critical molecule in resisting oxidative stress and maintaining the reducing environment of the cell.
The primary role of GSTs is to catalyze the conjugation of glutathione (GSH) with the electrophilic centers of a wide variety of molecules. The most commonly known substrates of GSTs are xenobiotic synthetic chemicals. There are also classes of GSTs that utilize glutathione as a cofactor rather than a substrate.
The detoxification reactions comprise the first four steps of mercapturic acid synthesis, [19] with the conjugation to GSH serving to make the substrates more soluble and allowing them to be removed from the cell by transporters such as multidrug resistance-associated protein 1 . [8]
The antioxidant enzyme glutathione peroxidase 4 (GPX4) belongs to the family of glutathione peroxidases, which consists of 8 known mammalian isoenzymes (GPX1–8).GPX4 catalyzes the reduction of hydrogen peroxide, organic hydroperoxides, and lipid peroxides at the expense of reduced glutathione and functions in the protection of cells against oxidative stress.