Structure of gel phase DMPC determined by X-ray diffraction
Structure of gel phase DMPC determined by X-ray diffraction
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DOI：
10.1016/s0006-3495(02)75333-2
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发表时间：
2002-12-01
影响因子：
3.4
通讯作者：
Nagle, JF
中科院分区：
文献类型：
--
作者：
Tristram-Nagle, S;Liu, YF;Nagle, JF
在10℃下得到了完全水合的凝胶相二肉豆浆酰基磷脂酰胆碱脂双层结构。定向脂质多层用于获得高信噪比数据。通过广角反射得到了链倾角和亚甲基电子密度的估计。在完全水化时，链的倾斜角为32.3±0.6度，从D = 59.9埃到D = 56.5 a的重复间距在轻度脱水时，链的倾斜角没有变化。用三种不同的方法制备了17种不同几何形状的D变量样品，得到了高达10阶的低角衍射峰。除了通常的傅里叶重建电子密度分布外，模型电子密度分布同时适合所有低角度数据，同时约束模型包括广角数据和测量的脂质体积。得到了面积/脂质（A = 47.2 +/- 0.5埃(2)）、压缩模量（K-A = 500 +/- 100 dyn/cm）、各种厚度(如碳氢化合物厚度（2D(C) = 30.3 +/- 0.2埃）和首尾间距（D-HH = 40.1 +/- 0.1埃）的结果。
The structure of fully hydrated gel phase dimyristoylphosphatidylcholine lipid bilayers was obtained at 10degreesC. Oriented lipid multilayers were used to obtain high signal-to-noise intensity data. The chain tilt angle and an estimate of the methylene electron density were obtained from wide angle reflections. The chain tilt angle is measured to be 32.3 +/- 0.6degrees near full hydration, and it does not change as the sample is mildly dehydrated from a repeat spacing of D = 59.9 Angstrom to D = 56.5 A. Low angle diffraction peaks were obtained up to the tenth order for 17 samples with variable D and prepared by three different methods with different geometries. In addition to the usual Fourier reconstructions of the electron density profiles, model electron density profiles were fit to all the low angle data simultaneously while constraining the model to include the wide-angle data and the measured lipid volume. Results are obtained for area/lipid (A = 47.2 +/- 0.5 Angstrom(2)), the compressibility modulus (K-A = 500 +/- 100 dyn/cm), various thicknesses, such as the hydrocarbon thickness (2D(C) = 30.3 +/- 0.2 Angstrom), and the head-to-head spacing (D-HH = 40.1 +/- 0.1 Angstrom).