Amine N-methyltransferase

In enzymology, an amine "N"-methyltransferase () is an enzyme that is ubiquitously present in non-neural tissues and that catalyzes the "N"-methylation of tryptamine and structurally related compounds.
The chemical reaction taking place is:
Thus, the two substrates of this enzyme are "S"-adenosyl methionine and amine, whereas its two products are "S"-adenosylhomocysteine and methylated amine. In the case of tryptamine and serotonin these then become the dimethylated indolethylamines "N","N"-dimethyltryptamine (DMT) and bufotenine.
This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is "S"-adenosyl--methionine:amine "N"-methyltransferase. Other names in common use include nicotine "N"-methyltransferase, tryptamine "N"-methyltransferase, indolethylamine "N"-methyltransferase, and arylamine "N"-methyltransferase. This enzyme participates in tryptophan metabolism.
A wide range of primary, secondary and tertiary amines can act as acceptors, including tryptamine, aniline, nicotine and a variety of drugs and other xenobiotics.
Structural studies.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code .