protein_function: Catalyzes the O-methylation, and thereby theinactivation, of catecholamine neurotransmitters and catecholhormones. Also shortens the biological half-lives of certainneuroactive drugs, like L-DOPA, alpha-methyl DOPA andisoproterenol.
Catechol-O-methyltransferase (COMT) is one of several enzymes that degrade catecholamines such as dopamine, epinephrine, and norepinephrine. In humans, catechol-O-methyltransferase protein is encoded by the COMT gene. As the regulation of catecholamines is impaired in a number of medical conditions, several pharmaceutical drugs target COMT to alter its activity and therefore the availability of catecholamines. In the brain, COMT-dependent dopamine degradation is of particular importance in brain regions with low expression of the presynaptic dopamine transporter (DAT), such as the prefrontal cortex. This process is supposed to take place in postsynaptic neurons, as, in general, COMT is located intracellularly in the central nervous system (CNS).