| EC |
1.14.16.4 |
| Accepted name: |
tryptophan 5-monooxygenase |
| Reaction: |
L-tryptophan + a 5,6,7,8-tetrahydropteridine + O2 = 5-hydroxy-L-tryptophan + a 4a-hydroxy-5,6,7,8-tetrahydropteridine |
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For diagram of biopterin biosynthesis, click here |
| Other name(s): |
L-tryptophan hydroxylase; indoleacetic acid-5-hydroxylase; tryptophan 5-hydroxylase; tryptophan hydroxylase |
| Systematic name: |
L-tryptophan,tetrahydropteridine:oxygen oxidoreductase (5-hydroxylating) |
| Comments: |
The active centre contains mononuclear iron(II). The enzyme is activated by phosphorylation, catalysed by a Ca2+-activated protein kinase. The 4a-hydroxytetrahydropteridine formed can dehydrate to 6,7-dihydropteridine, both spontaneously and by the action of EC 4.2.1.96, 4a-hydroxytetrahydrobiopterin dehydratase. The 6,7-dihydropteridine must be enzymically reduced back to tetrahydropteridine, by EC 1.5.1.34, 6,7-dihydropteridine reductase, before it slowly rearranges into the more stable but inactive compound 7,8-dihydropteridine. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9037-21-2 |
| References: |
| 1. |
Friedman, P.A., Kappelman, A.H. and Kaufman, S. Partial purification and characterization of tryptophan hydroxylase from rabbit hindbrain. J. Biol. Chem. 247 (1972) 4165–4173. [PMID: 4402511] |
| 2. |
Hamon, M., Bourgoin, S., Artaud, F. and Glowinski, J. The role of intraneuronal 5-HT and of tryptophan hydroxylase activation in the control of 5-HT synthesis in rat brain slices incubated in K+-enriched medium. J. Neurochem. 33 (1979) 1031–1042. [DOI] [PMID: 315449] |
| 3. |
Ichiyama, A., Nakamura, S., Nishizuka, Y. and Hayaishi, O. Enzymic studies on the biosynthesis of serotonin in mammalian brain. J. Biol. Chem. 245 (1970) 1699–1709. [PMID: 5309585] |
| 4. |
Jequier, E., Robinson, B.S., Lovenberg, W. and Sjoerdsma, A. Further studies on tryptophan hydroxylase in rat brainstem and beef pineal. Biochem. Pharmacol. 18 (1969) 1071–1081. [DOI] [PMID: 5789774] |
| 5. |
Wang, L., Erlandsen, H., Haavik, J., Knappskog, P.M. and Stevens, R.C. Three-dimensional structure of human tryptophan hydroxylase and its implications for the biosynthesis of the neurotransmitters serotonin and melatonin. Biochemistry 41 (2002) 12569–12574. [DOI] [PMID: 12379098] |
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| [EC 1.14.16.4 created 1972, modified 2003, modified 2019] |
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