Glutathione peroxidase 4(GPX4) is a kind of glutathione peroxidase containing selenocysteine, which can reduce phospholipid hydroperoxide to phosphatidyl alcohol, thus protecting the cell membrane from oxidative damage. GPX4 catalyzes the substrate, and the product consumes the reducing agent with the addition of enzyme reagents.The reducing agent has a maximum absorbance at 340 nm, and the GP4-specific enzyme activity can be calculated by measuring non-specific enzyme activity and total enzyme activity by adding GPX-4 inhibitor to the system.
