Purity: > 95% by SDS - PAGE Format: Liquid. In 20 mM Tris-HCl buffer (pH 8.0) containing 1 mM MgCl2, 10% glycerol. Catechol-O-methyltrasferase (COMT) is an enzyme that catalyses the transfer of the methyl group of S-adenosylmethionine (SAM) into catechol substrates such as levodopa, dopamine, epinephrine, and norepinephirine in the presence of Mg2+. COMT appears to be located in the postsynaptic neuron and plays roles in the metabolism of catechol estrogens and the inactivation of catecholamine neurotransmitters though enzymatic degradation. COMT inhibitors prevent levodopa degradation, increase its availability and are used in the treatment of patients with Parkinson's disease. Recombinant human COMT protein was expressed in E.coli and purified by using conventional chromatography techniques.