کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1927386 1536514 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Pulse radiolysis and steady-state analyses of the reaction between hydroethidine and superoxide and other oxidants
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Pulse radiolysis and steady-state analyses of the reaction between hydroethidine and superoxide and other oxidants
چکیده انگلیسی

Hydroethidine (HE) is a cell-permeable probe used for the intracellular detection of superoxide. Here, we report the direct measurement of the rate constant between hydroethidine and superoxide radical anion using the pulse radiolysis technique. This reaction rate constant was calculated to be ca. 2 × 106 M−1 s−1 in water:ethanol (1:1) mixture. The spectral characteristics of the intermediates indicated that the one-electron oxidation product of HE was different from the one-electron reduction product of ethidium (E+). The HPLC-electrochemical measurements of incubation mixtures containing HE and the oxygenated Fenton’s reagent (Fe2+/DTPA/H2O2) in the presence of aliphatic alcohols or formate as a superoxide generating system revealed 2-OH-E+ as a major product. Formation of 2-OH-E+ by the Fenton’s reagent without additives was shown to be superoxide dismutase-sensitive and we attribute the formation of superoxide radical anion to the one-electron reduction of oxygen by the DTPA-derived radical. Addition of tert-butanol, DMSO, and potassium bromide to the Fenton’s system caused inhibition of 2-OH-E+ formation. Results indicate that reducing and oxidizing radicals have differential effects on the formation of 2-OH-E+.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 456, Issue 1, 1 December 2006, Pages 39–47
نویسندگان
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