鄰苯二酚-o-甲基轉移酶催化甲基從s-腺苷蛋氨酸轉移到兒茶酚胺，包括神經遞質多巴胺、腎上腺素和去甲腎上腺素。這種O-甲基化導致兒茶酚胺遞質的主要降解途徑之一除了在內源性物質代謝中的作用外，comt在用于治療高血壓、哮喘和帕金森病的兒茶酚藥物代謝中也很重要。comt在組織中有兩種形式，可溶性形式（s-comt）和膜結合形式（mb-comt）。s-comt和mb-comt之間的差異存在于n-末端。通過使用替代翻譯起始位點和啟動子形成了幾個轉錄變體。[由RefSeq提供，2008年9月]
Catechol-O-methyltransferase catalyzes the transfer of a methyl group from S-adenosylmethionine to catecholamines, including the neurotransmitters dopamine, epinephrine, and norepinephrine. This O-methylation results in one of the major degradative pathways of the catecholamine transmitters. In addition to its role in the metabolism of endogenous substances, COMT is important in the metabolism of catechol drugs used in the treatment of hypertension, asthma, and Parkinson disease. COMT is found in two forms in tissues, a soluble form (S-COMT) and a membrane-bound form (MB-COMT). The differences between S-COMT and MB-COMT reside within the N-termini. Several transcript variants are formed through the use of alternative translation initiation sites and promoters. [provided by RefSeq, Sep 2008]