The Enzyme Database

Your query returned 1 entry.    printer_iconPrintable version

Accepted name: indoleamine 2,3-dioxygenase
Reaction: (1) D-tryptophan + O2 = N-formyl-D-kynurenine
(2) L-tryptophan + O2 = N-formyl-L-kynurenine
For diagram of tryptophan catabolism, click here
Other name(s): IDO (ambiguous); tryptophan pyrrolase (ambiguous); D-tryptophan:oxygen 2,3-oxidoreductase (decyclizing)
Systematic name: D-tryptophan:oxygen 2,3-oxidoreductase (ring-opening)
Comments: A protohemoprotein. Requires ascorbic acid and methylene blue for activity. This enzyme has broader substrate specificity than EC, tryptophan 2,3-dioxygenase [1]. It is induced in response to pathological conditions and host-defense mechanisms and its distribution in mammals is not confined to the liver [2]. While the enzyme is more active with D-tryptophan than L-tryptophan, its only known function to date is in the metabolism of L-tryptophan [2,6]. Superoxide radicals can replace O2 as oxygen donor [4,7].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9014-51-1
1.  Yamamoto, S. and Hayaishi, O. Tryptophan pyrrolase of rabbit intestine. D- and L-tryptophan-cleaving enzyme or enzymes. J. Biol. Chem. 242 (1967) 5260–5266. [PMID: 6065097]
2.  Yasui, H., Takai, K., Yoshida, R. and Hayaishi, O. Interferon enhances tryptophan metabolism by inducing pulmonary indoleamine 2,3-dioxygenase: its possible occurrence in cancer patients. Proc. Natl. Acad. Sci. USA 83 (1986) 6622–6626. [PMID: 2428037]
3.  Takikawa, O., Yoshida, R., Kido, R. and Hayaishi, O. Tryptophan degradation in mice initiated by indoleamine 2,3-dioxygenase. J. Biol. Chem. 261 (1986) 3648–3653. [PMID: 2419335]
4.  Hirata, F., Ohnishi, T. and Hayaishi, O. Indoleamine 2,3-dioxygenase. Characterization and properties of enzyme. O2- complex. J. Biol. Chem. 252 (1977) 4637–4642. [PMID: 194886]
5.  Dang, Y., Dale, W.E. and Brown, O.R. Comparative effects of oxygen on indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase of the kynurenine pathway. Free Radic. Biol. Med. 28 (2000) 615–624. [PMID: 10719243]
6.  Littlejohn, T.K., Takikawa, O., Truscott, R.J. and Walker, M.J. Asp274 and His346 are essential for heme binding and catalytic function of human indoleamine 2,3-dioxygenase. J. Biol. Chem. 278 (2003) 29525–29531. [PMID: 12766158]
7.  Thomas, S.R. and Stocker, R. Redox reactions related to indoleamine 2,3-dioxygenase and tryptophan metabolism along the kynurenine pathway. Redox Rep. 4 (1999) 199–220. [PMID: 10731095]
8.  Sono, M. Spectroscopic and equilibrium studies of ligand and organic substrate binding to indolamine 2,3-dioxygenase. Biochemistry 29 (1990) 1451–1460. [PMID: 2334706]
[EC created 2006]

Data © 2001–2018 IUBMB
Web site © 2005–2018 Andrew McDonald