Pascolini D, Blasie J K, Gruner S M
Biochim Biophys Acta. 1984 Oct 17;777(1):9-20. doi: 10.1016/0005-2736(84)90491-7.
Electron density profiles of disk membranes isolated from bovine retinal rod outer segments have been determined to 12 A resolution by analysis of the X-ray diffraction from oriented multilayers, in the absence of lipid phase separation. Data were collected on both film and a two-dimensional TV-detector; both detectors yielded identical patterns consisting of relatively sharp lamellar reflections of small mosaic spread. The unit cell repeat was reversibly varied over the range of 143 to 183 A. The diffraction patterns changed dramatically at 150 A; consequently, the low (less than 150 A) and high (greater than 150 A) periodicity data were independently analyzed via a swelling algorithm. The high periodicity data yielded two statistically equivalent phase choices corresponding to two symmetric, but different membrane profiles. The low periodicity data yielded essentially one, characteristically asymmetric profile. These profiles have been modeled with regard to the separate profiles of rhodopsin, lipid and water, subject to the known composition of the isolated disk membranes.
通过对取向多层膜的X射线衍射进行分析，在不存在脂质相分离的情况下，已确定从牛视网膜视杆外段分离出的盘膜的电子密度分布，分辨率达到12埃。在胶片和二维电视探测器上都收集了数据；两种探测器产生的图案相同，由具有小镶嵌展宽的相对尖锐的层状反射组成。晶胞重复在143至183埃的范围内可逆变化。衍射图案在150埃处发生了显著变化；因此，通过溶胀算法对低（小于150埃）和高（大于150埃）周期性数据进行了独立分析。高周期性数据产生了两个统计上等效的相位选择，对应于两个对称但不同的膜分布。低周期性数据基本上产生了一个特征性的不对称分布。根据视紫红质、脂质和水的单独分布，并考虑到分离的盘膜的已知组成，对这些分布进行了建模。
