Reduction of thymine hydroperoxide by phospholipid hydroperoxide glutathione peroxidase and glutathione transferases

Abstract
Thymine hydroperoxide (5‐hydroperoxymethyluracil), a model compound representing products of oxidative damage to DNA, is a substrate for glutathione peroxidase and some isoforms of glutathione transferase. In this paper, we show that selenium‐dependent human phospholipid hydroperoxide glutathione peroxidase (Se‐PHGPx) exhibits about four orders of magnitude higher activity on thymine hydroperoxide than that of other human enzymes such as selenium‐dependent glutathione peroxidase and various representatives of glutathione transferases. The results indicate that Se‐PHGPx may be an important enzyme in repairing oxidatively damaged DNA.