کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10738079 | 1046682 | 2011 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Oxidizing substrate specificity of Mycobacterium tuberculosis alkyl hydroperoxide reductase E: kinetics and mechanisms of oxidation and overoxidation
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
DTPABHTDTTDTNB15-HETEAhpE15-HPETE1,4-dithiothreitol - 1،4-dithiothreitol3-Chloroperoxybenzoic acid - 3-اسید کلرورپوکسین بنزوئیک5,5′-dithiobis-(2-nitrobenzoic acid) - 5،5'-dithiobis- (2-nitrobenzoic acid)α-linolenic acid - اسید α-لینولنیکArachidonic acid - اسید آراشیدونیکDiethylenetriamine pentaacetic acid - دی اتیلنتریامین پنتاتیک اسیدcumene hydroperoxide - هیدروپراکسید کومنbutylated hydroxytoluene - هیدروکسی تورولین باتلاقی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
سالمندی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Alkyl hydroperoxide reductase E (AhpE), a novel subgroup of the peroxiredoxin family, comprises Mycobacterium tuberculosis AhpE (MtAhpE) and AhpE-like proteins present in many bacteria and archaea, for which functional characterization is scarce. We previously reported that MtAhpE reacted ~ 103 times faster with peroxynitrite than with hydrogen peroxide, but the molecular reasons for that remained unknown. Herein, we investigated the oxidizing substrate specificity and the oxidative inactivation of the enzyme. In most cases, both peroxidatic thiol oxidation and sulfenic acid overoxidation followed a trend in which those peroxides with the lower leaving-group pKa reacted faster than others. These data are in agreement with the accepted mechanisms of thiol oxidation and support that overoxidation occurs through sulfenate anion reaction with the protonated peroxide. However, MtAhpE oxidation and overoxidation by fatty acid-derived hydroperoxides (~ 108 and 105 Mâ 1 sâ 1, respectively, at pH 7.4 and 25 °C) were much faster than expected according to the Brønsted relationship with leaving-group pKa. A stoichiometric reduction of the arachidonic acid hydroperoxide 15-HpETE to its corresponding alcohol was confirmed. Interactions of fatty acid hydroperoxides with a hydrophobic groove present on the reduced MtAhpE surface could be the basis of their surprisingly fast reactivity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Free Radical Biology and Medicine - Volume 51, Issue 2, 15 July 2011, Pages 464-473
Journal: Free Radical Biology and Medicine - Volume 51, Issue 2, 15 July 2011, Pages 464-473
نویسندگان
AnÃbal M. Reyes, MartÃn Hugo, Andrés Trostchansky, Luciana Capece, Rafael Radi, Madia Trujillo,