文章基本信息

标题：The effect of vitamin E on the structure of membrane lipid assemblies
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作者：A. Bradford ; J. Atkinson ; N. Fuller 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2003
卷号：44
期号：10
页码：1940-1945
DOI：10.1194/jlr.M300146-JLR200
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：The effects of vitamin E on the activity of membrane-dependent enzymes suggest that it acts indirectly by modifying some properties of the lipid host. The effects of α-tocopherol (α-T) and α-tocopherol hemisuccinate (α-THS) on phospholipid monolayer structure, curvature, and bending elasticity were examined using X-ray diffraction and the osmotic stress method. These ligands were mixed with the hexagonal phase-forming lipid, dioleoylphosphatidylethanolamine (DOPE). Increasing levels up to 50 mol% α-T in DOPE in excess water result in a systematic decrease in the lattice dimension. Analysis of the structural changes imposed by α-T shows that it contributes a spontaneous radius of curvature of −13.7 Å. This unusually negative value is comparable to diacylglycerols. α-T does not affect the bending elasticity of these monolayers. α-THS in its charged form decreases membrane curvature, but in its undissociated neutral form has a qualitatively similar but reduced effect on monolayer curvature, as does α-T. We discuss these results in terms of the local stresses such ligands would produce in the vicinity of a membrane protein, and how one might expect proteins to respond to such stress.