Glutathione Peroxidase: An Antioxidant Enzyme In Health And Disease Structural Basis for Catalytic Activity and Enzyme Polymerization of Phospholipid Hydroperoxide Glutathione Peroxidase 4 (GPx4),, Biochemistry Glutathione peroxidase 4 catalyzed reduction of lipid hydroperoxides in membranes: The polar head of membrane phospholipids binds the enzyme and addresses the fatty acid hydroperoxide group toward the redox center ScienceDirect 2OBI: Crystal structure of the Selenocysteine to Cysteine Mutant of human phospholipid hydroperoxide glutathione peroxidase (GPx4)