Selenoprotein (general class; e.g., Glutathione peroxidase, Thioredoxin reductase, Selenoprotein P)

Selenoproteins are a family of proteins that incorporate the trace element selenium in the form of the amino acid selenocysteine. These proteins play a critical role in reducing oxidative stress by acting as powerful antioxidants within cells. Key members include glutathione peroxidases and thioredoxin reductases, which neutralize hydrogen peroxide and lipid peroxides to prevent cellular damage. Selenoprotein P functions as a transporter for selenium throughout the body to ensure adequate distribution for antioxidant defense. The dynamic incorporation of selenocysteine into these enzymes enhances their catalytic efficiency and resistance to oxidative damage compared to cysteine-based counterparts, making them essential for maintaining redox balance under both normal and stress conditions. Dysregulation or deficiency in selenoproteins is implicated in various diseases including neurodegeneration, cardiovascular disorders, and cancer. While dietary selenium supports optimal function of these proteins, excessive intake can lead to toxicity.

Other names

SelenoproteinsSelenium-containing proteins

Cofactor for antioxidant enzymes that neutralize reactive oxygen species and peroxides