Page last updated: 2024-10-24

tryptophan 5-monooxygenase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: L-tryptophan + tetrahydrobiopterin + O2 = 5-hydroxy-L-tryptophan + 4-alpha-hydroxytetrahydrobiopterin + H2O. [EC:1.14.16.4]

Tryptophan 5-monooxygenase activity is a catalytic process that involves the incorporation of one atom of molecular oxygen into L-tryptophan, resulting in the formation of N-formylkynurenine. This enzyme belongs to the flavin-containing monooxygenase family and requires flavin adenine dinucleotide (FAD) as a cofactor. The reaction proceeds in two steps: 1) Reduction of FAD to FADH2 by NADPH, and 2) Oxidation of L-tryptophan by molecular oxygen to N-formylkynurenine. The mechanism involves the formation of a reactive oxygen species, likely a ferryl species, which is then used to oxidize the substrate. Tryptophan 5-monooxygenase activity is a key step in the kynurenine pathway, a major route for tryptophan catabolism in mammals. This pathway plays a role in various physiological processes, including neurotransmission, immune regulation, and redox homeostasis. Deficiency in tryptophan 5-monooxygenase activity can lead to a buildup of tryptophan and its metabolites, which may contribute to various disorders, such as neuropsychiatric conditions and autoimmune diseases. Conversely, excessive activity of this enzyme may be involved in the pathogenesis of certain cancers and inflammatory diseases.'
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Proteins (2)

ProteinDefinitionTaxonomy
Tryptophan 5-hydroxylase 1A tryptophan 5-hydroxylase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P17752]Homo sapiens (human)
Tryptophan 5-hydroxylase 2A tryptophan 5-hydroxylase 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8IWU9]Homo sapiens (human)

Compounds (2)

CompoundDefinitionClassesRoles
telotristattelotristat: a tryptophan hydroxylase inhibitorphenylalanine derivative
lp533401LP533401: Serotonin Agents; Tryptophan Hydroxylase inhibitor; structure in first source