Selenium-dependent glutathione peroxidasesA highlight of the role of phospholipid hydroperoxide glutathione peroxidase in protection against oxidative damage

Since the discovery that selenium is an integral component of the active site of the mammalian glutathione peroxidase, four members of the glutathione peroxidase family have been characterised: classical cellular glutathione peroxidase, gastrointestinal glutathione peroxidase; plasma glutathione peroxidase and phospholipid hydroperoxide glutathione peroxidase ( PHGPx) . They are products of different genes and have different specificities on hydrogen peroxide and lipid hydroperoxides, the latter are generated by free radicals and can damage cell membranes and disrupt cellular functions. Interestingly, PHGPx is not only active on phospholipid hydroperoxide, but also active on thymine hydroperoxide (a model compound for DNA damage) and protein hydroperoxides. This review highlights the role of PHGPx in protection against peroxidative damage of lipids, protein and DNA.