Ascorbate-dependent enzymes

Ascorbate-dependent enzymes are a heterogeneous group of enzymes that rely on ascorbate (vitamin C) as a cofactor or electron donor for catalytic activity[2][5][7][8]. Prominent examples include the 2-oxoglutarate-dependent dioxygenase family (such as prolyl hydroxylases involved in collagen biosynthesis and the TET family involved in DNA demethylation), ascorbate peroxidases (important for detoxifying hydrogen peroxide, especially in plants), dopamine β-hydroxylase (in catecholamine biosynthesis), and cytochrome b561 (in ascorbate recycling and iron absorption)[4][5][6][8]. The dependence on ascorbate arises from the need to maintain iron in the reduced Fe(II) state at the catalytic center. Dysregulation of these enzymes leads to diverse pathologies, including scurvy (impaired collagen synthesis), disrupted epigenetic regulation, and altered cell signaling in cancer and development. Ascorbate-dependent enzymes perform essential roles in oxidation-reduction reactions, antioxidant defenses, hormone synthesis, and epigenetic regulation in both animals and plants.

Other names

Ascorbate-dependent enzymesAscorbate-requiring enzymesVitamin C-dependent enzymesAscorbate-dependent oxidoreductases

Ascorbate acts as an electron donor, reducing Fe(III) to Fe(II) in the active center of many enzymes, maintaining catalytic activity and preventing inactivation[2][4][5][7][8].