The flavin-containing monooxygenases in rat liver: evidence for the expression of a second form different from FMO1

Biochem Biophys Res Commun. 1995 Jul 26;212(3):820-6. doi: 10.1006/bbrc.1995.2042.


A second form of rat liver FMO, FMO-A, was separated and purified by chromatography on Blue Sepharose Fast flow 6. This FMO-A is different from FMO1 by antigenic properties (anti-FMO-A did not cross-react with FMO1, and reciprocally) and by catalytic properties (the Km for trimethylamine was 3.8 microM and 141.4 microM for FMO-A and FMO1, respectively; the Km for imipramine was 536 microM and 17.4 microM for FMO-A and FMO1, respectively). Furthermore, N-terminal amino sequencing revealed differences in the primary structure of these two FMOs although they both contained the highly conserved FAD-binding domain (Gly-X-Gly-X-X-Gly).

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites / genetics
  • Cross Reactions
  • Gene Expression
  • Immunochemistry
  • In Vitro Techniques
  • Isoenzymes / genetics
  • Isoenzymes / isolation & purification*
  • Isoenzymes / metabolism
  • Kinetics
  • Male
  • Microsomes, Liver / enzymology*
  • Molecular Sequence Data
  • Molecular Weight
  • Oxygenases / genetics
  • Oxygenases / isolation & purification*
  • Oxygenases / metabolism
  • Rats
  • Substrate Specificity


  • Isoenzymes
  • Oxygenases
  • dimethylaniline monooxygenase (N-oxide forming)