Monoamine oxidase A

Target id: 2489

Nomenclature: Monoamine oxidase A

Abbreviated Name: MAO-A

Family: Catecholamine turnover

Annotation status:  image of a grey circle Awaiting annotation/under development. Please contact us if you can help with annotation.  » Email us

   GtoImmuPdb view: OFF :     Currently no data for Monoamine oxidase A in GtoImmuPdb

Gene and Protein Information
Species TM AA Chromosomal Location Gene Symbol Gene Name Reference
Human - 527 Xp11.4-p11.3 MAOA monoamine oxidase A
Mouse - 526 X A2 Maoa monoamine oxidase A
Rat - 526 Xq12 Maoa monoamine oxidase A
Database Links
ChEMBL Target
DrugBank Target
Ensembl Gene
Entrez Gene
Human Protein Atlas
KEGG Enzyme
RefSeq Nucleotide
RefSeq Protein
Enzyme Reaction
EC Number:
Description Reaction Reference
Dopamine -> 3,4-dihydroxyphenylacetaldehyde + NH3
(-)-Noradrenaline -> 3,4-dihydroxymandelic acid + NH3
(-)-Adrenaline -> 3,4-dihydroxymandelic acid + NH3
5-Hydroxytryptamine -> 5-hydroxyindole acetaldehyde + NH3
Tyramine -> 4-hydroxyphenyl acetaldehyde + NH3
Cofactor Species Comments Reference
flavin adenine dinucleotide Human

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Key to terms and symbols View all chemical structures Click column headers to sort
Ligand Sp. Action Affinity Units Reference
moclobemide Hs Inhibition 8.3 pKi 4
pKi 8.3 (Ki 5x10-9 M) [4]
phenelzine Hs Irreversible inhibition 7.3 pKi 2
pKi 7.3 (Ki 4.7x10-8 M) [2]
selegiline Hs Inhibition 4.2 pKi 6
pKi 4.2 (Ki 6.725x10-5 M) [6]
tranylcypromine Hs Inhibition 4.7 pIC50 8
pIC50 4.7 (IC50 2x10-5 M) [8]
clorgiline Hs Inhibition - -
befloxatone Hs Inhibition - - 3
pirlindole Hs Inhibition - - 5
Inhibitor Comments
Differential inhibition of the A or B isozymes of MAO have different clinical outcomes. Inhibition of MAOA results in antidepressant activity [1], whereas inhibition of MAOB results in antiparkinsonian activity [7]. Important substrates for MAO activity in the CNS include dopamine, adrenaline, noradrenaline, serotonin (5-HT), and β-phenylethylamine.
Tranylcypromine is an irreversible MAO inhibitor with equal potency for the A and B isozymes [8].
Clinically-Relevant Mutations and Pathophysiology
Disease:  Brunner syndrome
Synonyms: Monoamine oxidase A deficiency [Orphanet: ORPHA3057]
OMIM: 300615
Orphanet: ORPHA3057


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1. Binda C, Hubálek F, Li M, Herzig Y, Sterling J, Edmondson DE, Mattevi A. (2004) Crystal structures of monoamine oxidase B in complex with four inhibitors of the N-propargylaminoindan class. J. Med. Chem., 47 (7): 1767-74. [PMID:15027868]

2. Binda C, Wang J, Li M, Hubalek F, Mattevi A, Edmondson DE. (2008) Structural and mechanistic studies of arylalkylhydrazine inhibition of human monoamine oxidases A and B. Biochemistry, 47 (20): 5616-25. [PMID:18426226]

3. Curet O, Damoiseau-Ovens G, Sauvage C, Sontag N, Avenet P, Depoortere H, Caille D, Bergis O, Scatton B. (1998) Preclinical profile of befloxatone, a new reversible MAO-A inhibitor. J Affect Disord, 51 (3): 287-303. [PMID:10333983]

4. Jagrat M, Behera J, Yabanoglu S, Ercan A, Ucar G, Sinha BN, Sankaran V, Basu A, Jayaprakash V. (2011) Pyrazoline based MAO inhibitors: synthesis, biological evaluation and SAR studies. Bioorg. Med. Chem. Lett., 21 (14): 4296-300. [PMID:21680183]

5. Medvedev AE, Shvedov VI, Chulkova TM, Fedotova OA, Saederup E, Squires RF. (1998) The influence of the antidepressant pirlindole and its dehydro-derivative on the activity of monoamine oxidase A and GABAA receptor binding. J. Neural Transm. Suppl., 52: 337-42. [PMID:9564636]

6. Mishra N, Sasmal D. (2011) Development of selective and reversible pyrazoline based MAO-B inhibitors: virtual screening, synthesis and biological evaluation. Bioorg. Med. Chem. Lett., 21 (7): 1969-73. [PMID:21377879]

7. Tetrud JW, Langston JW. (1989) The effect of deprenyl (selegiline) on the natural history of Parkinson's disease. Science, 245 (4917): 519-22. [PMID:2502843]

8. Yoshida S, Rosen TC, Meyer OG, Sloan MJ, Ye S, Haufe G, Kirk KL. (2004) Fluorinated phenylcyclopropylamines. Part 3: Inhibition of monoamine oxidase A and B. Bioorg. Med. Chem., 12 (10): 2645-52. [PMID:15110846]

How to cite this page

Catecholamine turnover: Monoamine oxidase A. Last modified on 16/04/2015. Accessed on 17/07/2018. IUPHAR/BPS Guide to PHARMACOLOGY,