Amine N-methyltransferases from rabbit liver.

N-Methylation of amines has been ascribed to enzymes listed as amine N-methyltransferase, indolethylamine N-methyltransferase, and arylamine N-methyltransferase. All of these activities are accomplished by each of two related enzymes present in rabbit liver. The two N-methyltransferases have a very broad and overlapping specificity for primary and secondary amines. Both have a molecular mass of 30,000 daltons and react with an antibody formed to one of them, but have different isoelectric points.