Kynurenine aminotransferase 1 (KAT I)

Kynurenine aminotransferase 1 (KAT I) is a cytosolic, pyridoxal 5′-phosphate-dependent enzyme encoded by the CCBL1 gene in humans. It catalyzes the irreversible transamination of kynurenine to kynurenic acid, a key step in the kynurenine pathway which is involved in tryptophan metabolism. Kynurenic acid is an endogenous antagonist at NMDA (N-methyl-D-aspartate) and alpha-7 nicotinic acetylcholine receptors, and regulation of its concentrations in the brain has been implicated in the pathophysiology of schizophrenia, Alzheimer’s disease, Parkinson’s disease, and other neurodegenerative conditions. KAT I also has cysteine conjugate beta-lyase activity, participating in the metabolism of certain xenobiotics—which can lead to the formation of potentially toxic metabolites affecting both the nervous system and kidneys[1][3][8]. The enzyme is a homodimer with a characteristic aromatic-rich active site and broad substrate specificity for large neutral, aromatic, and sulfur-containing amino acids[1][4][6]. Abnormal enzyme activity or levels of its product, kynurenic acid, have been associated with disease processes, making it a potential target for therapeutic intervention and pharmacological modulation[7][1][3].

Other names

Glutamine transaminase KCysteine conjugate beta-lyase 1KYAT1CCBL1Kynurenine—oxoglutarate transaminase 1

Inhibition of enzyme activity (e.g., estrogen compounds inhibit by interacting with the active site)