Dimethylaniline monooxygenase [N-oxide-forming] 4 is an enzyme that in humans is encoded by the FMO4gene.
Metabolic N-oxidation of the diet-derived amino-trimethylamine (TMA) is mediated by flavin-containing monooxygenase and is subject to an inherited FMO3 polymorphism in man resulting in a small subpopulation with reduced TMA N-oxidation capacity resulting in fish odor syndrome Trimethylaminuria. Three forms of the enzyme, FMO1 found in fetal liver, FMO2 found in adult liver, and FMO3 are encoded by genes clustered in the 1q23-q25 region. Flavin-containing monooxygenases are NADPH-dependent flavoenzymes that catalyzes the oxidation of soft nucleophilic heteroatom centers in drugs, pesticides, and xenobiotics.
Itagaki K, Carver GT, Philpot RM (1996). "Expression and characterization of a modified flavin-containing monooxygenase 4 from humans". J. Biol. Chem.271 (33): 20102–7. doi:10.1074/jbc.271.33.20102. PMID8702731.
Janmohamed A, Dolphin CT, Phillips IR, Shephard EA (2001). "Quantification and cellular localization of expression in human skin of genes encoding flavin-containing monooxygenases and cytochromes P450". Biochem. Pharmacol.62 (6): 777–86. doi:10.1016/S0006-2952(01)00718-3. PMID11551524.
Furnes B, Feng J, Sommer SS, Schlenk D (2003). "Identification of novel variants of the flavin-containing monooxygenase gene family in African Americans". Drug Metab. Dispos.31 (2): 187–93. doi:10.1124/dmd.31.2.187. PMID12527699.