Native Bovine Phenylethanolamine N-Methyl Transferase

Phenylethanolamine N-methyltransferase (PNMT) is the enzyme which catalyzes the N-methylation of norepinephrine thereby resulting in the formation of epinephrine as shown below: Norepinephrine + S-Adenosyl methionine (SAM) -------> Epinephrine. The mechanism involves transfer of an active methyl group from S-adenosylmethionine (SAM) to the primary amino group of norepinephrine. Although it is primarily localized in the adrenal medulla, PNMT activity has also been demonstrated in the brain and heart tissues of several mammalian species including humans. PNMT purified from ox, rat and rabbit adrenal medulla have molecular weights in the range of 37,000-38,000. Analysis of PNMT activity could provide valuable information in the evaluation of catecholamine metabolism.