Open AccessSelenoproteins
Author(s) -
Svetlana Milanović,
Ivan Jovanović,
Olivera Valčić
Publication year - 2015
Publication title -
veterinarski glasnik
Language(s) - English
Resource type - Journals
eISSN - 2406-0771
pISSN - 0350-2457
DOI - 10.2298/vetgl1502075m
Subject(s) - selenocysteine , selenoprotein , biochemistry , selenium , chemistry , glutathione peroxidase , enzyme , peroxidase , amino acid , gpx1 , isozyme , gpx4 , iodothyronine deiodinase , glutathione , cysteine , hormone , thyroid hormones , deiodinase , organic chemistry
Selenium is an essential trace element with multi significant role in the body. In contrast to other trace elements that appear as cofactors of certain enzymes, its physiological role is directly related to functions of proteins in composition of which it is cotranslationally installed by atypical amino acid selenocysteine. The group of proteins, in which composition selenocysteine is an integral functional part of polypeptides, are referred to as selenoproteins. The first enzyme that has been proven to have selenocysteine incorporated in its composition, is glutathione peroxidase (GPx). So far there have been identified 5 isoenzyme forms of GPx which reduce hydrogen peroxide and organic hydroperoxides, protecting cells from oxidative damage. Iodothyronine deiodinases (ID) are among the most important selenopoteins, being responsible for both activation and deactivation of thyroid hormones. So far there have been found over twenty selenoproteins, but only for some of them a physiological role is known