Flavin adenine dinucleotide-dependent enzyme (FAD-dependent enzyme)

Flavin adenine dinucleotide-dependent enzymes are a broad superfamily of enzymes that require the redox-active cofactor FAD (derived from riboflavin, vitamin B2) for catalytic activity[4][6]. These enzymes participate in oxidation-reduction (redox) reactions essential for energy metabolism, including β-oxidation of fatty acids, amino acid catabolism, the citric acid cycle, and the electron transport chain[2][4][3][6]. FAD-dependent enzymes are structurally and functionally diverse and include oxidoreductases, monooxygenases, dehydrogenases, and certain DNA repair enzymes[6][3][5]. They are critical for both catabolic and anabolic pathways and can regulate or mediate electron transfer, oxygenation, and hydroxylation reactions[2][3][5]. Dysfunction or inhibition of specific FAD-dependent enzymes is implicated in metabolic disorders, cardiovascular disease, neurodegeneration, and cancer[2][4][3]. While this entry captures a class of enzymes rather than a single molecular entity, numerous FAD-dependent enzymes are themselves therapeutic targets[6][5]. As a result, "Flavin adenine dinucleotide-dependent enzyme" is not one single molecular target, but rather a collective term for a functionally defined family of enzymes dependent on FAD[4][6].

Other names

FlavoenzymeFlavin-dependent enzymeFAD-dependent oxidoreductaseFAD-dependent monooxygenaseFlavin adenine dinucleotide-dependent monooxygenase

Competitive inhibition (of substrate at enzyme active site, e.g., allopurinol for xanthine oxidase) Redox cycling or suicide inhibition (antineoplastic agents) Cofactor replacement or depletion (nutritional therapy with riboflavin)