Glutathione Peroxidase

Glutathione peroxidases (GPx) are a family of enzymes with the ability to reduce organic and inorganic hydroperoxides to the corresponding alcohols using glutathione or thioredoxin as an electron donor. These enzymes promote hydrogen peroxide metabolism and protect cell membrane structure and function from oxidative damage. Dysregulated GPx expression is connected with severe pathologies, including obesity and diabetes. GPx1 has been reported to be involved in both pro- and anticancer effects in different tumor models.

In mammals, the GPxs family consists of eight members (GPx1-GPx8) identified so far; five of them (GPx1-GPx4 and GPx6) contain selenocysteine in the catalytic center and the other three are cysteine-containing proteins. GPx1 is one of the most critical members of the GPxs family that catalytically reduces hydrogen peroxide to produce water. The function of GPx3 is to scavenge H2O2 and lipoperoxides in the plasma to reduce systematic oxidative stress and to maintain the bioavailability of vascular nitric oxide. Gpx4 is an essential mammalian glutathione peroxidase, which protects cells against detrimental lipid peroxidation and governs a novel form of regulated necrotic cell death, called ferroptosis.