A mutation in the flavin-containing monooxygenase 3 Gene and its effectson catalytic activity for N-oxidation of trimethylamine in vitro

摘要

To clarify the mutation of the flavin-containing monooxygenase (FMO)3 gene causing fishodor syndrome,we analyzed the FMO3 gene of a Thai subject who possibly suffered from fish-odor syndrome.A novel mutation,a single-base substitution from G to A at the position of 265(G265A),was ident(V58I).The mutated FMO3 protein with V58I exhibited the reduced triemthylamine N-oxidase activity when it was expressed in E.coli.The V_(max)/K_m value for the activity of the mutant-type FMO3 was about 5 tims lower than that for the wild-type FMO3.