Amine N-methyltransferase

Amine N-methyltransferase (EC 2.1.1.49), also called indolethylamine N-methyltransferase, and thioether S-methyltransferase, is an enzyme that is ubiquitously present in non-neural tissues and catalyzes the N-methylation of tryptamine and structurally related compounds.^[1] More recently, it was discovered that this enzyme can also catalyze the methylation of thioether and selenoether compounds, although the physiological significance of this biotransformation is not yet known.^[2][3]

amine N-methyltransferase
indolethylamine N-methyltransferase (with slight variation on CPK coloration) – See PDB 2A14​
Identifiers
EC no.	2.1.1.49
CAS no.	51377-47-0
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

The chemical reaction taking place is:

• S-adenosyl-L-methionine + an amine ${\displaystyle \rightleftharpoons }$ S-adenosyl-L-homocysteine + a methylated amine

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 respectively.^[4]

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-L-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.^[1]

Structural studies

As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 2A14.

See also

• Tryptamine