Monoamine oxidase is made up of an amino acid sequence. The exact structure of the molecule is not known but an experiment conducted by J. Wouters, R. Ramsey, E. Goormaghtigh and J.M. Rayssceaert sheds some light on the possible secondary structure of the macromolecule.

  • Both MAO-A and MAO-B contain a flavin-adenine dinucleotide cofactor ≥covalently bonded to MAO in thje C-terminal region through a thioether linkage from the 8-alpha-CH3 group of the flavin molecule to the cysteine peptide on the enzyme. Local peptides have also been established as follows:

  • Cloning of the cDNA for MAO A and MAO B shows that they are about 70% identical which most likely are derived from the same ancestral gene.

  • The N-terminus region is folded in a Beta-Alpha-Beta configuration much like other flavoproteins.

  • The secondary structures show different folding patterns especially between residues 100-200 which is likely the active sight. This hypothesis seems to agree with the majority of literature.

  • The AMP binding site (Rossman fold) serves also as the non-covalent binding site of FAD.

    A complete structure cannot be obtained until x-ray crystallography is used.

    At a later date you might be able to find the structure once it is determined. Here are some links to get you started.

    NIH Molecular Modeling

    Molecular Design Institute

    Enzyme Nomenclature Database (ExPASy)

    Go to Main Page