Anti-Catechol O-methyltransferase/COMT Antibody from rabbit, purified by affinity chromatography

Catechol O-methyltransferase (EC 2.1.1.6; UniProt P21964) is encoded by the COMT gene (Gene ID 1312) in human. Catechol-O-methyltransferase initiates the metabolic breakdown of catecholamines (including the neurotransmitters dopamine, epinephrine, and norepinephrine) by catalyzing the transfer of a methyl group from S-adenosylmethionine (SAM) to catecholamines in the presence Mg++. This O-methylation results in one of the major degradative pathways of the catecholamine transmitters. In addition to endogenous substances, COMT is also important in the metabolism of catechol drugs. Two isoforms exist as a result of alternative initiation codon usage. The membrane-bound isoform or MB-COMT contains a short N-terminal cytoplasmic tail (a.a. 1-6), a transmembrane segment (a.a. 7-26), and a large C-terminal extracellular region (a.a. 27-271), while the soluble or S-COMT isoform lacks the N-terminal 50-amino acid sequence of MB-COMT. MB-COMT and S-COMT differ in their substrate affinity and capacities. Despite having a lower capacity than S-COMT, MB-COMT has around a 10-fold greater affinity for dopamine and noradrenaline, and therefore is likely to be better suited for metabolizing catecholamines at the concentrations found in brain. The influence of the Val(158)Met polymorphic form of catechol-o-methyltransferase (COMT) on brain activation and functional connectivity is the subject of numerous studies.