کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1910950 1046794 2008 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Determining radical penetration of lipid bilayers with new lipophilic spin traps
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی سالمندی
پیش نمایش صفحه اول مقاله
Determining radical penetration of lipid bilayers with new lipophilic spin traps
چکیده انگلیسی

Predicting the susceptibility of lipid moieties to radical attack requires a determination of the depth of radical penetration into a lipid membrane. We thus synthesized three homologous series of lipophilic spin traps—DMPO analogs 2-alkanoyl-2-methyl-1-pyrroline N-oxides (11) and PBN derivatives 4-alkoxyphenyl N-tert-butylnitrones (18) and 4-alkoxyphenyl N-admantylnitrones (20). The intercalation depth of these spin traps within the liposomal bilayer was determined via the previously reported NMR technique, which correlates the chemical shift and the micropolarity (measured in ET(30) units) experienced by the pivotal nitronyl carbon. Hydroxyl and α-hydroxyalkyl radicals were generated in the extraliposomal aqueous phase and the lowest depth at which a radical could be spin trapped was determined. The ESR data indicate that these radicals can exit the aqueous phase, penetrate the lipid bilayer past the head groups (ET(30) = 63 kcal/mol) and the glycerol ester (ET(30) = 52 kcal/mol), and pass down to an ET(30) polarity of at least 44 kcal/mol. The latter depth presumably corresponds to the upper portion of the lipid slab. It is likely, if not probable, that having come this far they can abstract the allylic/diallylic hydrogens resident in the midslab at ET(30) values of > 31 kcal/mol.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Free Radical Biology and Medicine - Volume 44, Issue 7, 1 April 2008, Pages 1394–1405
نویسندگان
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