کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10772295 1050850 2005 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Loss of the tyrosyl radical in mouse ribonucleotide reductase by (−)-epicatechin
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Loss of the tyrosyl radical in mouse ribonucleotide reductase by (−)-epicatechin
چکیده انگلیسی
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 × 10−4 and 2 × 10−4 s−1for 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.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 326, Issue 3, 21 January 2005, Pages 614-617
نویسندگان
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