3-hydroxykynureninase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: L-3-hydroxykynurenine + H2O = 3-hydroxyanthranilate + L-alanine. [PMID:17300176]

3-Hydroxykynureninase (EC 3.7.1.3) is a pyridoxal phosphate-dependent enzyme that catalyzes the hydrolytic cleavage of 3-hydroxykynurenine to alanine and 3-hydroxyanthranilate. This reaction is a key step in the kynurenine pathway, which is a major route of tryptophan catabolism in mammals. 3-hydroxykynureninase is a member of the α-amino acid racemase superfamily and shares a common structural motif with other pyridoxal phosphate-dependent enzymes, such as kynureninase and alanine racemase. The active site of the enzyme contains a pyridoxal phosphate cofactor that is essential for catalysis. The mechanism of the reaction involves the formation of a Schiff base intermediate between the pyridoxal phosphate cofactor and the amino group of 3-hydroxykynurenine. This Schiff base is then hydrolyzed to release alanine and 3-hydroxyanthranilate. 3-hydroxykynureninase activity is essential for the proper function of the kynurenine pathway and is therefore involved in a variety of physiological processes, including the biosynthesis of nicotinamide adenine dinucleotide (NAD+), the regulation of immune responses, and the protection against oxidative stress.'
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Proteins (1)

Compounds (3)