Search results
Results from the WOW.Com Content Network
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.
In humans, glutathione synthetase functions in a similar manner. Its product GSH participates in cellular pathways involved in homeostasis and cellular maintenance. For instance, glutathione peroxidases catalyze the oxidation of GSH to glutathione disulfide (GSSG) by reducing free radicals and reactive oxygen species such as hydrogen peroxide. [18]
GCL is exclusively located in plastids, and glutathione synthetase (GS) is dual-targeted to plastids and cytosol, thus GSH and gamma-glutamylcysteine are exported from the plastids. [28] Studies also shown that restricting GCL activity to the cytosol or glutathione biosynthesis to the plastids is sufficient for normal plant development and ...
Glutathione peroxidase 4 (GPx4) has a high preference for lipid hydroperoxides; it is expressed in nearly every mammalian cell, though at much lower levels. Glutathione peroxidase 2 is an intestinal and extracellular enzyme, while glutathione peroxidase 3 is extracellular, especially abundant in plasma. [ 4 ]
In plants, the glutathione-ascorbate cycle operates in the cytosol, mitochondria, plastids and peroxisomes. [5] [6] Since glutathione, ascorbate and NADPH are present in high concentrations in plant cells it is assumed that the glutathione-ascorbate cycle plays a key role for H 2 O 2 detoxification.
The proportion of cell volume that is cytosol varies: for example while this compartment forms the bulk of cell structure in bacteria, [9] in plant cells the main compartment is the large central vacuole. [10] The cytosol consists mostly of water, dissolved ions, small molecules, and large water-soluble molecules (such as proteins).
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.
[13] [19] Specifically, the function of GSTs in this role is twofold: to bind both the substrate at the enzyme's hydrophobic H-site and GSH at the adjacent, hydrophilic G-site, which together form the active site of the enzyme; and subsequently to activate the thiol group of GSH, enabling the nucleophilic attack upon the substrate. [12]