Nomenclature	Common abbreviation	HGNC, UniProt	EC number	Cofactors	Selective inhibitors (pIC50)	Comment
Catechol-O-methyltransferase	COMT	COMT, P21964	2.1.1.6: dopamine -> 3-methoxytyramine	S-adenosyl methionine	entacapone 52,54, tolcapone 52,54	COMT appears to exist in both membrane-bound and soluble forms. COMT has also been described to methylate steroids, particularly hydroxyestradiols, Reaction 1: dopamine -> 3-methoxytyramine, Reaction 2: (-)-noradrenaline -> normetanephrine, Reaction 3: (-)-adrenaline -> metanephrine, Reaction 4: 3,4-dihydroxymandelic acid -> vanillylmandelic acid