Purification and properties of phenylethanolamine-N-methyl transferase.

The methylation of norepinephrine to epinephrine was first demonstrated by Biilbring with the use of minced adrenal gland and adenosine triphosphate (2). Soon after, Keller, Boissonnas, and du Vigneaud (3) showed that the methyl group of methionine is incorporated into the epinephrine of the adrenal gland in the intact animal. Subsequently, S-adenosylmethionine was shown to be the methyl donor in the N-methylation of norepinephrine to epinephrine (4). This report will describe the assay, purification, properties, and distribution of an enzyme, phenylethanolamine-N-methyl transferase, that N-methylates the nitrogen of norepinephrine as well as that of a number of phenylethanolamine derivatives.