Editorial, J Metabonomics Metabolites Vol: 1 Issue: 2
Tryptophan Metabolism- Indoleamine 2,3-Dioxygenase- Friend and Foe
| Nesrine Kamal Bassal, Bernard P Hughes* and Maurizio Costabile |
| University of South Australia, School of Pharmacy and Medical Sciences, Adelaide, Australia |
| Corresponding author : Bernard P Hughes, Ph.D University of South Australia, School of Pharmacy and Medical Sciences, Adelaide, SA 5000, Australia Tel: +61883022310; Fax: +61883022389; E-mail: Bernie.Hughes@unisa.edu.au |
| Received: November 12, 2012 Accepted: November 14, 2012 Published: November 16, 2012 |
| Citation: Bassal NK, Hughes BP, Costabile M (2012) Tryptophan Metabolism-Indoleamine 2,3-Dioxygenase- Friend and Foe. J Metabonomics Metabolites 1:2. doi:10.4172/2325-9736.1000e107 |
Abstract
Tryptophan Metabolism- Indoleamine 2,3-Dioxygenase- Friend and Foe
Indoleamine 2,3-dioxygenase (IDO) (EC 1.13.11.42) is a cytoplasmic, heme-containing enzyme that mediates the initial and rate-limiting step in the oxidative catabolism of the essential amino acid L-tryptophan (L-Trp). Recently, an additional IDO molecule, termed IDO2 has been identified. The gene encoding IDO2 is adjacent to the IDO gene. The IDO2 protein has a different expression profile to IDO and while it is able to metabolize L-Trp, IDO2 has a much higher Km for this substrate. In addition both enzymes differ in their selectivity for some inhibitors. Degradation of L-Trp via IDO leads to the production of several metabolites, including N-formyl-kynurenine and Kynurenine (Kyn).
