MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:

Enzymes and Genes:

Homo sapiens: catechol O-methyltransferase, membrane-bound formInferred from experiment: COMT

In Pathway: dopamine degradation, betaxanthin biosynthesis

Note that this reaction equation differs from the official Enzyme Commission reaction equation for this EC number, which can be found here .

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.

Most BioCyc compounds have been protonated to a reference pH value of 7.3. Please see the PGDB Concepts Guide for more information.

Mass balance status: Balanced.

Direct generic reaction:
a catechol + S-adenosyl-L-methionine → a guaiacol + S-adenosyl-L-homocysteine + H+ (

Enzyme Commission Primary Name: catechol O-methyltransferase

Enzyme Commission Synonyms: COMT I , COMT II, S-COMT (soluble form of catechol-O-methyltransferase), MB-COMT (membrane-bound form of catechol-O-methyltransferase), catechol methyltransferase, catecholamine O-methyltransferase

Standard Gibbs Free Energy (ΔrG in kcal/mol): -4.3600006Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
The mammalian enzyme acts more rapidly on catecholamines such as adrenaline or noradrenaline than on catechols.

Citations: [Axelrod58, Gulliver79, Huh79]

Gene-Reaction Schematic

Gene-Reaction Schematic

Unification Links: KEGG:R04301

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:


Axelrod58: Axelrod J, Tomchick R (1958). "Enzymatic O-methylation of epinephrine and other catechols." J Biol Chem 233(3);702-5. PMID: 13575440

Gulliver79: Gulliver PA, Tipton KF (1979). "The purification and properties of pig brain catechol-o-methyltransferase." J Neurochem 32(5);1525-9. PMID: 438821

Huh79: Huh MM, Friedhoff AJ (1979). "Multiple molecular forms of catechol-O-methyltransferase. Evidence for two distinct forms, and their purification and physical characterization." J Biol Chem 254(2);299-308. PMID: 762061

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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