Selenium-dependent enzyme

Selenium-dependent enzymes are a group of enzymes that require selenium, typically in the form of the amino acid selenocysteine, for their catalytic function. These include several important families such as glutathione peroxidases, which protect cells from oxidative damage by reducing hydrogen peroxide and organic hydroperoxides; thioredoxin reductases, which maintain cellular redox balance; and thyroid hormone deiodinases, which regulate activation and deactivation of thyroid hormones. In humans, at least 25 selenoproteins are encoded in the genome. These enzymes play critical roles in antioxidant defense, redox homeostasis, thyroid function, immune response modulation, and DNA synthesis. Dysregulation or deficiency can contribute to diseases such as cancer, cardiovascular disorders, inflammatory conditions like Hashimoto’s thyroiditis, and others. While essential for health at trace levels due to their role in these vital processes, excessive selenium intake can be toxic. The drug ebselen acts as a glutathione peroxidase mimetic by catalyzing destruction of hydrogen peroxide. Note: For structured databases or therapeutic targeting purposes it is preferable to refer to specific members such as "Glutathione peroxidase 1", "Thioredoxin reductase 1", etc., rather than the broad category "Selenium-dependent enzyme systems".

Other names

SelenoenzymeSelenoprotein (when referring to the protein family)Selenium-containing enzyme

Antioxidant activity via reduction of peroxides and hydroperoxides