Spaar Alexander, Salditt Tim
Experimentalphysik, Universität des Saarlandes, Im Stadtwald, D-66123 Saarbrücken, Germany.
Biophys J. 2003 Sep;85(3):1576-84. doi: 10.1016/S0006-3495(03)74589-5.
We present a study of the short range ordering of hydrocarbon chains in phospholipid bilayers. The x-ray peak associated with the hydrocarbon chains has been probed by means of reciprocal space mappings. Using 20 keV undulator radiation and samples of negligible mosaicity (orientational disorder), the intensity distribution is probed as a function of two coordinates, the momentum transfer parallel and perpendicular to the bilayer, over a wide range and at high resolution. Structural results are obtained concerning the distribution of tilted segments, the correlation length and the radial distribution function of the quasi two-dimensional liquid structure. A comparison is made with published molecular dynamics data (H. Heller, M. Schaefer, and K. Schulten. 1993. J. Phys. Chem. 97:8343-8360) by direct Fourier transformation of the atomic coordinates. The exact prefactor in the relationship between interchain distance and peak position is derived.
我们展示了一项关于磷脂双层中烃链短程有序性的研究。通过倒易空间映射对与烃链相关的X射线峰进行了探测。使用20keV的波荡器辐射和取向无序可忽略不计的样品，在很宽的范围内并以高分辨率探测强度分布作为平行和垂直于双层的两个坐标的函数。获得了关于倾斜段分布、关联长度和准二维液体结构的径向分布函数的结构结果。通过对原子坐标进行直接傅里叶变换，与已发表的分子动力学数据（H. Heller、M. Schaefer和K. Schulten。1993年。《物理化学杂志》97:8343 - 8360）进行了比较。推导了链间距离与峰位置之间关系中的精确前置因子。
