|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 188.8.131.52
In Pathway: dopamine degradation
Note that this reaction equation differs from the official Enzyme Commission reaction equation for this EC number, which can be found here .
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. 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+ (184.108.40.206)
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
Enzyme Commission Summary:
The mammalian enzyme acts more rapidly on catecholamines such as adrenaline or noradrenaline than on catechols.
Instance reactions of [a catechol + S-adenosyl-L-methionine → a guaiacol + S-adenosyl-L-homocysteine + H+] (220.127.116.11):
i1: 3,4-dihydroxyphenylglycol + S-adenosyl-L-methionine → 3-methoxy-4-hydroxyphenylglycol + S-adenosyl-L-homocysteine + H+ (18.104.22.168)
i2: 3,4-dihydroxymandelate + S-adenosyl-L-methionine → vanillyl mandelate + S-adenosyl-L-homocysteine + H+ (22.214.171.124)
i3: 3,4-dihydroxyphenylacetate + S-adenosyl-L-methionine → homovanillate + S-adenosyl-L-homocysteine + H+ (126.96.36.199)
i4: S-adenosyl-L-methionine + dopamine → S-adenosyl-L-homocysteine + 3-methoxytyramine + H+ (188.8.131.52)
i5: (R)-adrenaline + S-adenosyl-L-methionine → metanephrine + S-adenosyl-L-homocysteine + H+ (184.108.40.206)
i6: (R)-noradrenaline + S-adenosyl-L-methionine → normetanephrine + S-adenosyl-L-homocysteine + H+ (220.127.116.11)
i7: L-dopa + S-adenosyl-L-methionine → 3-O-methyldopa + S-adenosyl-L-homocysteine + H+ (18.104.22.168)
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
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