|Gene:||GPX1||Accession Number: G-7533 (MetaCyc)|
Species: Homo sapiens
Subunit composition of
glutathione peroxidase 1 = [GPX1]4
glutathione peroxidase 1 subunit = GPX1
Glutathione peroxidases (GPxs) are a family of enzymes that scavenge peroxides generated in cells. Some isozymes have selenium-dependent glutathione peroxidase activity and contain selenocysteine encoded by a TGA codon, while others do not contain selenocysteine [Arthur00a]. There are four major selenium dependent GPx isozymes in mammalian tissues; classical GPx (GPx-1; E.C. 220.127.116.11), gastrointestinal GPx (GPx-2), plasma GPx (GPx-3), and phospholipid GPx (GPx-4; E.C. 18.104.22.168). GPx-1, 2, and 3 act as homotetramers, while GPx-4 as a monomer [Arthur00a].
In addition to the selenium-containing GPXs and the proteins which contain cysteine and have similar structures to the GPXs, there are many selenium independent GPX activities in mammalian systems. These activities are mainly associated with the glutathione-S-transferase family of enzymes, whose activity is directed mainly towards organic hydroperoxides, and not hydrogen peroxide.
Gene Citations: [Sukenaga87]
Molecular Weight of Polypeptide: 21.899 kD (from nucleotide sequence), 23 kD (experimental) [Rey94 ]
Molecular Weight of Multimer: 92 kD (experimental) [Rey94]
pI: 5.1 [Rey94]
Unification Links: ArrayExpress:P07203 , ModBase:P07203 , PhosphoSite:P07203 , PhylomeDB:P07203 , Pride:P07203 , Protein Model Portal:P07203 , SMR:P07203 , String:9606.ENSP00000407375 , Swiss-Model:P07203 , UniProt:P07203
Relationship Links: Entrez-Nucleotide:PART-OF:Y00433 , InterPro:IN-FAMILY:IPR000889 , InterPro:IN-FAMILY:IPR012336 , Panther:IN-FAMILY:PTHR11592 , PDB:Structure:2F8A , Pfam:IN-FAMILY:PF00255 , Prints:IN-FAMILY:PR01011 , Prosite:IN-FAMILY:PS00460 , Prosite:IN-FAMILY:PS00763 , Prosite:IN-FAMILY:PS51355
|MultiFun Terms:||cell processes → protection → detoxification|
Enzymatic reaction of: glutathione peroxidase
Synonyms: classical GPX
EC Number: 22.214.171.124
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
The reaction is favored in the direction shown.
Mills first described GPX activity in 1957 [Mills57], and predicted it to be responsible for the protection of red blood cells against haemolysis by oxidation. The enzyme, now called GPX-1, was originally called glutathione peroxidase, and also classical GPX, cytosolic or cellular GPX. GPX-1 can metabolize hydrogen peroxide and a range of organic peroxides, including cholesterol and long-chain fatty acid peroxides. However, unless accompanied by phospholipase A2 activity to release the fatty acids, GPX-1 cannot metabolize fatty acid hydroperoxides in phospholipids [Grossmann83]. GPX-1 can interact with a wide range of organic hydroperoxides as well as hydrogen peroxide. Despite this range of peroxide substrates, it is very specific for glutathione as reducing substrate [Arthur00a].
pH(opt): 8.5 [Rey94]
Rey94: Rey C, Vericel E, Nemoz G, Chen W, Chapuy P, Lagarde M (1994). "Purification and characterization of glutathione peroxidase from human blood platelets. Age-related changes in the enzyme." Biochim Biophys Acta 1226(2);219-24. PMID: 8204670
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