Structure of human monoamine oxidase B, a drug target for the treatment of neurological disorders

Nat Struct Biol. 2002 Jan;9(1):22-6. doi: 10.1038/nsb732.


Monoamine oxidase B (MAO B) is a mitochondrial outermembrane flavoenzyme that is a well-known target for antidepressant and neuroprotective drugs. We determined the structure of the human enzyme to 3 A resolution. The enzyme binds to the membrane through a C-terminal transmembrane helix and apolar loops located at various positions in the sequence. The electron density shows that pargyline, an analog of the clinically used MAO B inhibitor, deprenyl, binds covalently to the flavin N5 atom. The active site of MAO B consists of a 420 A(3)-hydrophobic substrate cavity interconnected to an entrance cavity of 290 A(3). The recognition site for the substrate amino group is an aromatic cage formed by Tyr 398 and Tyr 435. The structure provides a framework for probing the catalytic mechanism, understanding the differences between the B- and A-monoamine oxidase isoforms and designing specific inhibitors.

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Catalysis
  • Cell Membrane / metabolism
  • Crystallography, X-Ray
  • Drug Design
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Monoamine Oxidase / chemistry*
  • Monoamine Oxidase / metabolism
  • Monoamine Oxidase Inhibitors / chemistry
  • Monoamine Oxidase Inhibitors / metabolism
  • Nervous System Diseases / drug therapy
  • Nervous System Diseases / enzymology*
  • Protein Binding
  • Protein Structure, Secondary
  • Structure-Activity Relationship
  • Substrate Specificity


  • Monoamine Oxidase Inhibitors
  • Monoamine Oxidase

Associated data

  • PDB/1GOS