Acid-induced change in ozone-reactive site in indole ring of tryptophan
- Department of Pathema Analysis, Kobe University Graduate School of Health Sciences, 7-10-2 Tomogaoka, Suma, Kobe 645-0142 (Japan)
- Department of Medical Risk Management, Faculty of Risk Management, Chiba Institute of Science, Choshi, Chiba 288-0025 (Japan)
- Department of Legal Medicine, Aichi Medical School, Nagakute, Aichi 480-1195 (Japan)
It is well established that ozone as well as oxygen activated by tryptophan 2,3-dioxygenase or indoleamine 2,3-dioxygenase cleave the 2,3-C=C bond of the indole ring of tryptophan to produce N-formylkynurenine. In the present study, however, we found that exposure of tryptophan to aqueous ozone at and below pH 4.5 generated a different compound. The compound was identified as kynurenine by high performance liquid chromatography and mass spectrometry. Exposure of N-formylkynurenine to acidic ozone did not generate a significant amount of kynurenine, indicating that the kynurenine was not produced via N-formylkynurenine. Acidic ozone thus appears to cleave the 1, 2-N-C bond in place of the 2,3-C=C bond of the indole ring, followed by liberation of the 2-C atom. The 1,2-N-C bond and 2,3-C=C bond are likely to undergo changes in their nature of bonding on acidification, enabling ozone to react with the former bond but not with the latter bond.
- OSTI ID:
- 21255924
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 380, Issue 3; Other Information: DOI: 10.1016/j.bbrc.2009.01.087; PII: S0006-291X(09)00139-9; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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