Acid-induced change in ozone-reactive site in indole ring of tryptophan.
Biochem Biophys Res Commun
; 380(3): 498-502, 2009 Mar 13.
Article
em En
| MEDLINE
| ID: mdl-19250632
ABSTRACT
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-NAC 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-NAC 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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ozônio
/
Triptofano
/
Indóis
/
Cinurenina
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article