Ascorbate-dependent enzyme and antioxidant pathway

The term "Ascorbate-dependent enzymes/antioxidant pathways" refers to a broad group of **enzymes** that require ascorbate (vitamin C) as a cofactor, along with the associated **cellular antioxidant systems** in which ascorbate plays a central role. This is not a single molecular target but rather encompasses multiple distinct proteins—primarily Fe(II)- and 2‑oxoglutarate–dependent dioxygenases such as prolyl hydroxylases, TET DNA demethylases, dopamine β-hydroxylase, peptidylglycine α-amidating monooxygenase—and the broader biochemical network responsible for maintaining redox balance through free radical scavenging. As an **enzyme cofactor**, ascorbate is essential for collagen synthesis, carnitine biosynthesis, neurotransmitter production (e.g., norepinephrine), peptide hormone amidation, tyrosine metabolism, DNA demethylation via TET enzymes, and more. Its primary biochemical function is to act as an electron donor—reducing metal ions within enzyme active sites or directly neutralizing reactive oxygen species. In its role within **antioxidant pathways**, it protects cells from oxidative damage by scavenging free radicals directly or by regenerating other antioxidants such as α-tocopherol. Deficiency in these pathways can contribute to diseases including scurvy (from impaired collagen synthesis), increased oxidative stress-related disorders like cardiovascular disease or neurodegeneration due to insufficient antioxidant protection; conversely high-dose vitamin C has been explored therapeutically in cancer due to potential prooxidant effects at pharmacological concentrations. Because this entry describes a class of molecules/processes rather than one specific protein or receptor target suitable for drug development or biomarker use—and because it combines both individual enzymes with entire metabolic/defense networks—it should be considered an incorrect entry if strict molecular targeting information is required. “Ascorbate acts both directly—as an electron donor reducing oxidized molecules—and indirectly by serving as a cofactor for numerous monooxygenase/dioxygenase enzymes involved in critical biosynthetic processes… The term ‘ascorbate-dependent enzyme/antioxidant pathway’ thus refers not to one molecule but many.”

Other names

Vitamin C-dependent enzymesAscorbate pathwayVitamin C antioxidant system

Cofactor for Fe(II)- and 2-oxoglutarate-dependent dioxygenases; Electron donor in enzymatic reactions