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Information on EC 1.4.3.4 - monoamine oxidase and Organism(s) Homo sapiens and UniProt Accession P27338
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1.4.3.4 monoamine oxidaseIUBMB Comments
A mitochondrial outer-membrane flavoprotein (FAD) that catalyses the oxidative deamination of neurotransmitters and biogenic amines . Acts on primary amines, and also on some secondary and tertiary amines. It differs from EC 1.4.3.21, primary-amine oxidase as it can oxidize secondary and tertiary amines but not methylamine. This enzyme is inhibited by acetylenic compounds such as chlorgyline, 1-deprenyl and pargyline but, unlike EC 1.4.3.21 and EC 1.4.3.22 (diamine oxidase), it is not inhibited by semicarbazide.
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Word Map
- 1.4.3.4
- dopamine
-
antidepressant
- parkinsonism
- platelet
-
dopaminergic
-
neurotransmitter
-
tricyclic
- norepinephrine
- pargyline
-
reuptake
- deprenyl
-
deamination
- clorgyline
- catecholamine
- noradrenaline
- 5-hydroxytryptamine
-
neuroprotective
-
serotonergic
- striatal
-
anxiety
-
psychiatric
- l-dopa
- fluoxetine
- catechol-o-methyltransferase
- 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
-
biogenic
- levodopa
-
mood
- reserpine
- imipramine
-
monoaminergic
- tryptamine
-
3,4-dihydroxyphenylacetic
- benzodiazepine
- mpp+
- amphetamine
-
nigrostriatal
-
homovanillic
-
5-hydroxyindoleacetic
-
noradrenergic
-
dopac
- 5-hydroxytryptophan
- 1-methyl-4-phenylpyridinium
- paroxetine
- desipramine
-
electroconvulsive
-
panic
-
mptp-induced
-
anticholinergic
-
antidepressant-like
- drug development
- analysis
- synthesis
- medicine
The taxonomic range for the selected organisms is: Homo sapiens
The expected taxonomic range for this enzyme is: Bacteria, Eukaryota, Archaea
The expected taxonomic range for this enzyme is: Bacteria, Eukaryota, Archaea
Synonyms
monoamine oxidase, mao-b, mao-a, monoamine oxidase a, mao a, mao b, monoamine oxidase b, monoamine oxidase-b, monoamine oxidase-a, semicarbazide-sensitive amine oxidase, 
more
topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
MAO B
-
MAO-B
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672579, 684233, 684261, 684862, 685418, 685540, 685839, 686193, 686264, 686347, 686554, 686571, 687244, 688267, 688477, 688603, 689175, 689204, 689716, 702565, 704855, 705020, 705940, 711424, 711911, 720287, 720626, 742064, 742065, 742443, 764270, 764275, 764276, 764555, 765139, 765219, 765252, 765254
monoamine oxidase B
-
adrenaline oxidase
-
-
-
-
epinephrine oxidase
-
-
-
-
MAO
MAO A
MAO B
MAO-A
MAO-B
-
-
MAOA
MAOB
monoamine oxidase
monoamine oxidase A
monoamine oxidase B
monoamine oxidase-A
monoamine:O2 oxidoreductase (deaminating)
-
-
-
-
serotonin deaminase
-
-
-
-
tyraminase
-
-
-
-
tyramine oxidase
-
-
-
-
additional information
MAO
-
-
-
-
MAO A
-
MAO-A
-
-
MAO-A
-
MAOA
-
monoamine oxidase
-
-
-
-
monoamine oxidase A
-
-
monoamine oxidase A
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394552, 671913, 672530, 672531, 674429, 684301, 684305, 684308, 684810, 685243, 685418, 685838, 685839, 685879, 686325, 686347, 686478, 686554, 687244, 687285, 688260, 688478, 688543, 689205, 689207, 689711, 689834, 689835, 702297, 702546, 703615, 703627, 703657, 742443, 742446, 764275, 764276, 764293
monoamine oxidase B
-
-
additional information
-
MAO-A and MAO-B are 2 different isoenzymic forms which differ in substrate specificity, distribution among tissues and their structures
additional information
-
the N-terminal region of the two isoenzymes is not involved in the different specificity of the two isoenzymes for substrates and inhibitors
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
RCH2NHR' + H2O + O2 = RCHO + R'NH2 + H2O2
mechanism of monoamine oxidase A and B
-
RCH2NHR' + H2O + O2 = RCHO + R'NH2 + H2O2
catalysis occur via proton abstraction mechanisms
RCH2NHR' + H2O + O2 = RCHO + R'NH2 + H2O2
reaction mechanism of C-H bond cleavage, overview. MAO oxidation of benzylamines and phenethylamines exhibit large deuterium kinetic isotope effects showing, in most instances, that C-H bond cleavage is rate limiting in catalysis
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REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Deamination
-
-
-
-
redox reaction
-
-
-
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oxidation
-
-
-
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reduction
-
-
-
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PATHWAY SOURCE
PATHWAYS
KEGG
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Arginine and proline metabolism, Biosynthesis of secondary metabolites, Isoquinoline alkaloid biosynthesis, Isoquinoline alkaloid biosynthesis, Isoquinoline alkaloid biosynthesis, Isoquinoline alkaloid biosynthesis, Isoquinoline alkaloid biosynthesis, Phenylalanine metabolism, Phenylalanine metabolism, Phenylalanine metabolism, Phenylalanine metabolism, Phenylalanine metabolism
SYSTEMATIC NAME
IUBMB Comments
amine:oxygen oxidoreductase (deaminating)
A mitochondrial outer-membrane flavoprotein (FAD) that catalyses the oxidative deamination of neurotransmitters and biogenic amines [3]. Acts on primary amines, and also on some secondary and tertiary amines. It differs from EC 1.4.3.21, primary-amine oxidase as it can oxidize secondary and tertiary amines but not methylamine. This enzyme is inhibited by acetylenic compounds such as chlorgyline, 1-deprenyl and pargyline but, unlike EC 1.4.3.21 and EC 1.4.3.22 (diamine oxidase), it is not inhibited by semicarbazide.
CAS REGISTRY NUMBER
COMMENTARY
9001-66-5
-
SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
(1R,6S)-3-methyl-6-phenyl-3-aza-bicyclo[4.1.0]heptane + H2O + O2
?
MAO-B catalyzed ring alpha-carbon oxidation of 3-methyl-6-phenyl-3-aza-bicyclo[4.1.0]heptane is enantioselective with an almost 5fold preference for the (1R,6S) enantiomer based on Vmax/Km values
-
-
?
(1S,6R)-3-methyl-6-phenyl-3-azabicyclo[4.1.0]heptane + H2O + O2
?
MAO-B catalyzed ring alpha-carbon oxidation of 3-methyl-6-phenyl-3-aza-bicyclo[4.1.0]heptane is enantioselective with an almost 5fold preference for the (1R,6S) enantiomer based on Vmax/Km values
-
-
?
1-methyl-4-(1-methyl-1H-pyrrol-2-yl)-1,2,3,6-tetrahydropyridine + H2O + O2
?
-
-
-
?
3-(4-(3-aminopropoxy)butoxy)-N-(thiophen-2-ylmethyl)propan-1-amine + H2O + O2
3-(4-[3-[(thiophen-2-ylmethyl)amino]propoxy]butoxy)propanal + NH3 + H2O2
-
-
-
?
4-phenylbutylamine + H2O + O2
4-phenylbutanal + NH3 + H2O2
proposed pathways for amine oxidation: the amine substrate may bind to oxidised enzyme (E/FADox), leading to the release of product imine via a binary (1) or ternary (2) pathway. The relative contributions of these pathways cannot be determined directly by steady-state approaches. In following pathway 1, the unoccupied reduced enzyme (E/FADred) is generated, to which substrate may also bind. Reoxidation of the E/FADredâS species (pathway 3) bypasses direct regeneration of E/FADox, with the consequence that imine released subsequent to this step, whether through the binary or ternary pathways leading from E/FADredâimine, is a product of substrate binding to a second enzyme species
-
-
?
4-tyramine + H2O + O2
2-(4-hydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
N1-(thiophen-2-ylmethyl)dodecane-1,12-diamine + H2O + O2
12-[(thiophen-2-ylmethyl)amino]dodecanal + NH3 + H2O2
-
-
-
?
N1-benzyl-N1-methyldodecane-1,12-diamine + H2O + O2
12-[benzyl(methyl)amino]dodecanal + NH3 + H2O2
-
-
-
?
N1-benzyldodecane-1,12-diamine + H2O + O2
12-(benzylamino)dodecanal + NH3 + H2O2
-
-
-
?
p-nitrophenylethylamine + H2O + O2
4-nitrophenylacetaldehyde + NH3 + H2O2
good substrate for wild-type and mutant enzymes Y435H, Y435F, Y435L and Y435W
-
-
?
p-trifluoromethyl-benzylamine + H2O + O2
4-trifluoromethylbenzaldehyde + NH3 + H2O2
-
-
-
?
serotonin + H2O + O2
(5-hydroxy-1H-indol-3-yl)acetaldehyde + NH3 + H2O2
-
-
-
r
1-methyl-4-(1-methyl-1H-pyrrol-2-yl)-1,2,3,6-tetrahydropyridine + H2O + O2
?
-
-
-
?
1-methyl-4-(1-methylpyrrol-2-yl)-1,2,3,6-tetrahydropyridine + H2O + O2
?
-
i.e. MMTP, is oxidized to the corresponding dihydropyridinium metabolite, MMDP+
-
-
?
1-[4-(trifluoromethyl)phenyl]methanamine + H2O + O2
4-(trifluoromethyl)benzaldehyde + NH3 + H2O2
-
-
-
-
?
2 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine + 2 H2O + 3 O2
1-methyl-4-phenyl-2,3-dihydropyridinium + 1-methyl-4-phenylpyridinium + 4 H2O2
3-(4-(3-aminopropoxy)butoxy)-N-(thiophen-2-ylmethyl)propan-1-amine + H2O + O2
3-(4-[3-[(thiophen-2-ylmethyl)amino]propoxy]butoxy)propanal + NH3 + H2O2
-
-
-
?
4-tyramine + H2O + O2
(4-hydroxyphenyl)acetaldehyde + NH3 + H2O2
substrate for isoform MAO A
-
-
?
4-tyramine + H2O + O2
2-(4-hydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
5-hydroxytryptamine + H2O + O2
(5-hydroxy-1H-indol-3-yl)acetaldehyde + NH3 + H2O2
-
-
-
-
?
kynuramine + O2
4-hydroxyquinoline + NH3 + H2O2
-
-
-
-
?
N1-(thiophen-2-ylmethyl)dodecane-1,12-diamine + H2O + O2
12-[(thiophen-2-ylmethyl)amino]dodecanal + NH3 + H2O2
-
-
-
?
N1-benzyl-N1-methyldodecane-1,12-diamine + H2O + O2
12-[benzyl(methyl)amino]dodecanal + NH3 + H2O2
-
-
-
?
N1-benzyldodecane-1,12-diamine + H2O + O2
12-(benzylamino)dodecanal + NH3 + H2O2
-
-
-
?
1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine + H2O + O2
?
1-methyl-4-phenylpyridinium is the ultimate product
-
-
?
2-phenylethylamine + H2O + O2
2-phenylethanal + NH3 + H2O2
-
-
-
?
2-phenylethylamine + H2O + O2
2-phenylethanal + NH3 + H2O2
proposed pathways for amine oxidation: the amine substrate may bind to oxidised enzyme (E/FADox), leading to the release of product imine via a binary (1) or ternary (2) pathway. The relative contributions of these pathways cannot be determined directly by steady-state approaches. In following pathway 1, the unoccupied reduced enzyme (E/FADred) is generated, to which substrate may also bind. Reoxidation of the E/FADredâS species (pathway 3) bypasses direct regeneration of E/FADox, with the consequence that imine released subsequent to this step, whether through the binary or ternary pathways leading from E/FADredâimine, is a product of substrate binding to a second enzyme species
-
-
?
4-tyramine + H2O + O2
(4-hydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
benzylamine + H2O + O2
benzaldehyde + NH3 + H2O2
monoamine oxidase B
-
-
?
benzylamine + H2O + O2
benzaldehyde + NH3 + H2O2
monoamine oxidase B
-
-
?
benzylamine + H2O + O2
benzaldehyde + NH3 + H2O2
insights into the interactions that take place on activation of the amine substrate by the aromatic cage residues in MAO-B Tyr398 and Try435
-
-
?
benzylamine + H2O + O2
benzaldehyde + NH3 + H2O2
proposed pathways for amine oxidation: the amine substrate may bind to oxidised enzyme (E/FADox), leading to the release of product imine via a binary (1) or ternary (2) pathway. The relative contributions of these pathways cannot be determined directly by steady-state approaches. In following pathway 1, the unoccupied reduced enzyme (E/FADred) is generated, to which substrate may also bind. Reoxidation of the E/FADredâS species (pathway 3) bypasses direct regeneration of E/FADox, with the consequence that imine released subsequent to this step, whether through the binary or ternary pathways leading from E/FADredâimine, is a product of substrate binding to a second enzyme species
-
-
?
benzylamine + H2O + O2
benzaldehyde + NH3 + H2O2
substrate for isoform MAO B
-
-
?
dopamine + H2O + O2
(3,4-dihydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
dopamine + H2O + O2
(3,4-dihydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
4-hydroxyquinoline + NH3 + H2O2
a method is decribed to measure MAO activity and inhibition based on the oxidation of kynuramine determined by HPLC-DAD, combined in the same assay with the oxidation of a peroxidase substrate
-
-
?
p-nitrobenzylamine + H2O + O2
4-nitrobenzaldehyde + NH3 + H2O2
poor substrate for wild-type enzyme and mutant enzymes Y435H and Y435F
-
-
?
p-nitrobenzylamine + H2O + O2
4-nitrobenzaldehyde + NH3 + H2O2
insights into the interactions that take place on activation of the amine substrate by the aromatic cage residues in MAO-B Tyr398 and Try435
-
-
?
1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine + H2O + O2
?
-
-
-
-
?
2 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine + 2 H2O + 3 O2
1-methyl-4-phenyl-2,3-dihydropyridinium + 1-methyl-4-phenylpyridinium + 4 H2O2
-
activation of the neurotoxin to neurotoxic pyridinium cations. MPTP easily crosses the blood-brain barrier and is preferentially metabolized by MAO-B present in glial cells to 1-methyl-4-phenyl-2,3-dihydropyridinium. This enzymatic metabolite is subsequently oxidized to 1-methyl-4-phenylpyridinium, which is selectively uptaken by dopaminergic cells, producing inhibition of complex I of mitochondria, energy depletion, oxidative stress and cell death
1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine is metabolically oxidized by alpha-carbon oxidation by MAO enzymes to give 1-methyl-4-phenyl-2,3-dihydropyridinium and hydrogen peroxide, which, in a further step, is readily oxidized to 1-methyl-4-phenylpyridinium, that is a directly-acting neurotoxic substance
-
?
2 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine + 2 H2O + 3 O2
1-methyl-4-phenyl-2,3-dihydropyridinium + 1-methyl-4-phenylpyridinium + 4 H2O2
-
activation of the neurotoxin to neurotoxic pyridinium cations
-
-
?
2-phenylethylamine + H2O + O2
2-phenylethanal + NH3 + H2O2
-
MAO-B selective substrate
-
?
2-phenylethylamine + H2O + O2
2-phenylethanal + NH3 + H2O2
-
MAO-B selective substrate
-
?
4-tyramine + H2O + O2
4-hydroxyphenylacetaldehyde + NH3 + H2O2
-
-
-
-
?
4-tyramine + H2O + O2
4-hydroxyphenylacetaldehyde + NH3 + H2O2
-
in vivo activity, overview
-
-
?
4-tyramine + H2O + O2
4-hydroxyphenylacetaldehyde + NH3 + H2O2
-
substrate for both hMAO-A and hMAO-B
-
-
?
5-methoxy-N,N-dimethyltryptamine + H2O + O2
?
-
i.e. 5-MeO-DMT, a psychoactive indolealkylamine drug found in a variety of plant preparations, e.g. Virola snuffs and Ayahuasca, and venom of psychoactive toads, e.g. Colorado River Bufo alvarius. 5-MeO-DMT is known as a nonselective 5-HT receptor agonist. MAO-A eliminates the drug 5-MeO-DMT through oxidative deamination
-
-
?
5-methoxy-N,N-dimethyltryptamine + H2O + O2
?
-
i.e. 5-MeO-DMT, a psychoactive indolealkylamine drug found in a variety of plant preparations, e.g. Virola snuffs and Ayahuasca, and venom of psychoactive toads, e.g. Colorado River Bufo alvarius
-
-
?
dopamine + H2O + O2
(3,4-dihydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
dopamine + H2O + O2
(3,4-dihydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
dopamine + H2O + O2
(3,4-dihydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
dopamine + H2O + O2
(3,4-dihydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
-
?
dopamine + H2O + O2
(3,4-dihydroxyphenyl)acetaldehyde + NH3 + H2O2
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
MAO-A
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
-
MAO-A
-
-
?
kynuramine + H2O + O2
3-(2-aminophenyl)-3-oxopropanal + NH3 + H2O2
monoamine oxidase A
-
-
?
kynuramine + H2O + O2
4-hydroxyquinoline + NH3 + H2O2
a method is decribed to measure MAO activity and inhibition based on the oxidation of kynuramine determined by HPLC-DAD, combined in the same assay with the oxidation of a peroxidase substrate
-
-
?
phenylethylamine + H2O + O2
2-phenylethanal