Loss of the tyrosyl radical in mouse ribonucleotide reductase by (-)-epicatechin.
Biochem Biophys Res Commun
; 326(3): 614-7, 2005 Jan 21.
Article
en En
| MEDLINE
| ID: mdl-15596143
The flavonoid (-)-epicatechin was previously demonstrated to interfere with tyrosine nitration by peroxynitrite [Biochem. Biophys. Res. Commun. 285 (2001) 782]. This effect was hypothesized to be based upon an interaction of epicatechin with a transiently generated tyrosyl radical. In the present study, using electron paramagnetic resonance, we demonstrate that (-)-epicatechin is capable of destabilizing the tyrosyl radical of the mouse ribonucleotide reductase R2 component. First-order rate constants for the disappearance of tyrosyl radical signals were 1 x 10(-4) and 2 x 10(-4)s(-1)for epicatechin and hydroxyurea, a well-known tyrosyl radical scavenger, respectively. In keeping with scavenging the ribonucleotide reductase tyrosyl radical, cellular production of deoxyribonucleotides and DNA synthesis were impaired by (-)-epicatechin in normal human keratinocytes and in human squamous carcinoma cells.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ribonucleótido Reductasas
/
Tirosina
/
Catequina
Límite:
Animals
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2005
Tipo del documento:
Article
País de afiliación:
Alemania