In
enzymology
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
, a kynurenine-oxoglutarate transaminase () is an
enzyme 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 recyc ...
the
chemical reaction
:-kynurenine + 2-oxoglutarate 4-(2-aminophenyl)-2,4-dioxobutanoate + -glutamate
Thus, the two
substrates of this enzyme are
-kynurenine and
2-oxoglutarate, whereas its two
products are
4-(2-aminophenyl)-2,4-dioxobutanoate and
-glutamate. The former product is an unstable α-oxo acid that quickly undergoes intramolecular cyclization to form
kynurenic acid.
This enzyme belongs to the family of
transferases, to be specific, the
transaminases, that transfer nitrogenous groups. The
systematic name of this enzyme class is -kynurenine:2-oxoglutarate aminotransferase. Other names in common use include kynurenine transaminase (cyclizing), kynurenine 2-oxoglutarate transaminase, kynurenine aminotransferase, and -kynurenine aminotransferase. This enzyme participates in
tryptophan metabolism. It employs one
cofactor,
pyridoxal phosphate.
KYAT1
Kynurenine—oxoglutarate transaminase 1 is an enzyme that in humans is encoded by the ''CCBL1'' gene. It is one of the Kynurenine—oxoglutarate transaminases.
This gene encodes a cytosolic enzyme which is responsible for the metabolism of c ...
,
AADAT (aka KYAT2), and
KYAT3
Kynurenine aminotransferase 3 is an enzyme that in humans is encoded by the ''KYAT3'' gene. It is one of the Kynurenine—oxoglutarate transaminase
In enzymology, a kynurenine-oxoglutarate transaminase () is an enzyme that catalyzes the chemi ...
are examples of enzymes of this class.
GOT2 (aka KYAT4) is also believed to catalyze the above reaction.
Structural studies
As of early 2009, 18
structures have been solved for this class of enzymes, with
PDB accession codes , , , , , , , , , , , , , , , , , and .
References
Further reading
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EC 2.6.1
Enzymes of known structure
Pyridoxal phosphate enzymes
{{2.6-enzyme-stub