Glutathione peroxidase 2 is an enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 that in humans is encoded by the GPX2 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

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The antioxidant

Antioxidant

An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

 enzyme glutathione peroxidase 2 (Gpx2) is one out of eight known glutathione peroxidases (Gpx1-8) in humans. Mammalian Gpx1

GPX1

Glutathione peroxidase 1 is an enzyme that in humans is encoded by the GPX1 gene.-Further reading:...

, GPx2 (this protein), Gpx3, and Gpx4

GPX4

Glutathione peroxidase 4, also known as GPX4, is an enzyme that in humans is encoded by the GPX4 gene. GPX4 is a phospholipid hydroperoxidase that protects cells against membrane lipid peroxidation.- Function :...

 have been shown to be selenium

Selenium

Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...

-containing enzymes, whereas Gpx6 is a selenoprotein

Selenoprotein

In molecular biology a selenoprotein is any protein that includes a selenocysteine amino acid residue. Among functionally characterized selenoproteins are five glutathione peroxidases and three thioredoxin reductases, which both contain only one Se-Cys. Selenoprotein P is the most common...

 in humans with cysteine-containing homologues in rodents. In selenoproteins, the 21st amino acid selenocysteine

Selenocysteine

Selenocysteine is an amino acid that is present in several enzymes .-Nomenclature:...

 is inserted in the nascent polypeptide chain during the process of translational recoding of the UGA stop codon

Stop codon

In the genetic code, a stop codon is a nucleotide triplet within messenger RNA that signals a termination of translation. Proteins are based on polypeptides, which are unique sequences of amino acids. Most codons in messenger RNA correspond to the addition of an amino acid to a growing polypeptide...

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Further reading