Determination of molecular order in supported lipid membranes by internal reflection Fourier transform infrared spectroscopy.
Determination of molecular order in supported lipid membranes by internal reflection Fourier transform infrared spectroscopy.
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DOI：
10.1016/s0006-3495(96)79380-3
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发表时间：
1996-10
影响因子：
3.4
通讯作者：
Mario J. Citra;P. Axelsen
中科院分区：
文献类型：
--
作者：
Mario J. Citra;P. Axelsen
当偏振内反射红外光谱法用于确定支持的脂质膜中的分子顺序时，结果严重依赖于关于膜中的倏逝电场振幅的假设的准确性。在这项工作中，我们研究了几个表达式用于计算支持的脂质单层和双层的倏逝电场振幅，并测试其有效性，通过测量的聚-γ-苄基-L-谷氨酸和聚-β-苄基-L-天冬氨酸的红外二色性的条件下，其分子顺序是已知的。我们的研究结果表明，处理这样的系统作为一个简单的单一界面之间的两个半无限体相是更准确的比常用的薄膜近似。这意味着早期的结论支持脂质膜的分子顺序可能需要大量的修订。
When polarized internal reflection infrared spectroscopy is used to determine molecular order in supported lipid membranes, the results are critically dependent on the accuracy of assumptions made about the evanescent electric field amplitudes in the membrane. In this work, we examine several expressions used for calculating evanescent electric field amplitudes in supported lipid monolayers and bilayers, and test their validity by measuring the infrared dichroism of poly-gamma-benzyl-L-glutamate and poly-beta-benzyl-L-aspartate under conditions in which their molecular order is known. Our results indicate that treating such systems as a simple single interface between two semi-infinite bulk phases is more accurate than the commonly employed thin-film approximation. This implies that earlier conclusions about molecular order in supported lipid membranes may require substantial revision.