Flavin-containing monooxygenase 1 (FMO1)

Flavin-containing monooxygenase 1 (FMO1) is a NADPH-dependent enzyme primarily expressed in fetal liver, kidney, and some extrahepatic tissues. It catalyzes the oxidative metabolism (oxygenation) of a wide range of xenobiotics and endogenous substrates containing soft nucleophilic centers, particularly nitrogen and sulfur atoms. This enzyme is important for phase I drug metabolism, facilitating the detoxification and excretion of drugs, pesticides, and dietary compounds. FMO1, along with closely related isoforms FMO2 and FMO3, is involved in the conversion of trimethylamine (TMA) to its N-oxide (TMAO), and polymorphisms in these enzymes are associated with disorders like trimethylaminuria. FMO1 operates through a catalytic mechanism involving FAD and NADPH, and its activity can influence individual drug responses and susceptibility to drug-induced toxicity[1][3][5][6][7].

Other names

Dimethylaniline monooxygenase [N-oxide-forming] 1Dimethylaniline oxidase 1Fetal hepatic flavin-containing monooxygenase 1Trimethylamine monooxygenaseFMO 1

Catalyzes N- and S-oxygenation, converting lipophilic xenobiotics into more polar metabolites for excretion[1][3][5]. Uses FAD and NADPH as cofactors to insert an oxygen atom onto soft nucleophilic heteroatoms (primarily nitrogen and sulfur) in substrates[2][3][5].