Glutathione Peroxidase 3/GPX3: ProductsGlutathione Peroxidase 3 (GPX3), also known as Plasma Glutathione Peroxidase, is a 226 amino acid member of the glutathione peroxidase antioxidant enzyme family. The Glutathione Peroxidase family protects cell surfaces, extracellular fluid components, and enzymes from oxidative stress by catalysing the reduction of hydrogen peroxide, lipid peroxides, and organic hydroperoxide using reduced glutathione. GPX3 is secreted into plasma and like GPX1, is an ~100 kDa homotetramer consisting of four identical 23 kDa subunits, each containing a selenocysteine residue at the active site. GPX3 exhibits highest levels of mRNA expression in liver (human only), kidney, heart and lung tissues. Mouse GPX3 shares 89% and 99% amino acid identity with human and rat GPX3, respectively.