tryptophan 5-monooxygenase | |||||||||
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Identifiers | |||||||||
EC number | 1.14.16.4 | ||||||||
CAS number | 9037-21-2 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
Gene Ontology | AmiGO / EGO | ||||||||
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Search | |
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PMC | articles |
PubMed | articles |
NCBI | proteins |
tryptophan hydroxylase 1 (tryptophan 5-monooxygenase) | |
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Identifiers | |
Symbol | TPH1 |
Alt. symbols | TPRH, TPH |
Entrez | 7166 |
HUGO | 12008 |
OMIM | 191060 |
PDB | 1MLW |
RefSeq | NM_004179 |
UniProt | P17752 |
Other data | |
EC number | 1.14.16.4 |
Locus | Chr. 11 p15.3-p14 |
tryptophan hydroxylase 2 | |
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Identifiers | |
Symbol | TPH2 |
Entrez | 121278 |
HUGO | 20692 |
OMIM | 607478 |
RefSeq | NM_173353 |
UniProt | Q8IWU9 |
Other data | |
Locus | Chr. 12 q15 |
Tryptophan hydroxylase (TPH) is an enzyme (EC 1.14.16.4) involved in the synthesis of the neurotransmitter serotonin. Tyrosine hydroxylase, phenylalanine hydroxylase, and tryptophan hydroxylase together constitute the family of biopterin-dependent aromatic amino acid hydroxylases. TPH catalyzes the following chemical reaction
It employs one additional cofactor, iron.
It is responsible for addition of the -HO group (hydroxylation) to the 5 position to form the amino acid 5-hydroxytryptophan (5-HTP), which is the initial and rate-limiting step in the synthesis of the neurotransmitter serotonin. It is also the first enzyme in the synthesis of melatonin.
Tryptophan hydroxylase (TPH), tyrosine hydroxylase (TH) and phenylalanine hydroxylase (PAH) are members of a superfamily of aromatic amino acid hydroxylases, catalyzing key steps in important metabolic pathways. Analogously to phenylalanine hydroxylase and tyrosine hydroxylase, this enzyme uses (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH4) and dioxygen as cofactors.
In humans, the stimulation of serotonin production by administration of tryptophan has an antidepressant effect and inhibition of tryptophan hydroxylase (e.g. by p-Chlorophenylalanine) may precipitate depression.