Monoamine oxidase A and B (MAO A and B) are major neurotransmitter- and xenobiotic-metabolizing enzymes that are thought to play a role in psychiatric and neurological disorders. These isozymes have a high degree of identity in their nucleotide deduced amino acid sequences, but are encoded by different genes on the X-chromosome. Previous studies on MAO B have shown that FAD binds both noncovalently and covalently to specific amino acid residues that reside in highly conserved regions of MAO A and B. In the instant invention, it is demonstrated that the aromatic moieties at Tyr<193> and Tyr<398>, which are located on each side of the covalent FAD binding residue (Cys<397>) participate in covalent FAD binding, and the generation of catalytically active MAO B.
TYR<393> AND TYR<398> MUTANTS OF MONOAMINE OXIDASE B