In
enzymology, an amine ''N''-methyltransferase () is an enzyme that is ubiquitously present in non-neural tissues and that
catalyzes
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycl ...
the ''N''-
methylation
In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These t ...
of
tryptamine
Tryptamine is an indolamine metabolite of the essential amino acid, tryptophan. The chemical structure is defined by an indole ─ a fused benzene and pyrrole ring, and a 2-aminoethyl group at the second carbon (third aromatic atom, with the f ...
and structurally related compounds.
The chemical reaction taking place is:
*
''S''-adenosyl-L-methionine + an
amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent su ...
''S''-adenosyl-L-homocysteine + a
methylated
In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These te ...
amine
Thus, the two
substrates of this enzyme are
''S''-adenosyl methionine and
amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent su ...
, whereas its two
products
Product may refer to:
Business
* Product (business), an item that serves as a solution to a specific consumer problem.
* Product (project management), a deliverable or set of deliverables that contribute to a business solution
Mathematics
* Produ ...
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
Bufotenin (5-HO-DMT, bufotenine) is a tryptamine derivative - more specifically, a DMT derivative - related to the neurotransmitter serotonin. It is an alkaloid found in some species of toads (especially the skin), mushrooms and plants.
The n ...
.
This enzyme belongs to the family of
transferase
A transferase is any one of a class of enzymes that catalyse the transfer of specific functional groups (e.g. a methyl or glycosyl group) from one molecule (called the donor) to another (called the acceptor). They are involved in hundreds of ...
s, specifically those transferring one-carbon group methyltransferases. The
systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature.
A semisystematic name or semitrivial ...
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
Tryptophan (symbol Trp or W)
is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic ...
.
A wide range of primary, secondary and tertiary amines can act as
acceptors, including tryptamine,
aniline
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine. It is an industrially significant commodity chemical, as well as a versatile start ...
,
nicotine and a variety of drugs and other
xenobiotic
A xenobiotic is a chemical substance found within an organism that is not naturally produced or expected to be present within the organism. It can also cover substances that are present in much higher concentrations than are usual. Natural compo ...
s.
Structural studies
As of late 2007, only one
structure has been solved for this class of enzymes, with the
PDB accession code .
See also
*
Tryptamine
Tryptamine is an indolamine metabolite of the essential amino acid, tryptophan. The chemical structure is defined by an indole ─ a fused benzene and pyrrole ring, and a 2-aminoethyl group at the second carbon (third aromatic atom, with the f ...
References
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External links
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EC 2.1.1
Enzymes of known structure