Funk J, Welte W, Hodapp N, Wutschel I, Kreutz W
Biochim Biophys Acta. 1981 Jan 8;640(1):142-58. doi: 10.1016/0005-2736(81)90540-x.
The structure of the rod outer segment disc-membrane in vivo was studied by X-ray low-angle scattering. The experiments were made on frogs under narcosis. Diffraction patterns corresponding to a resolution of 1.5 nm could be obtained from the membrane stacks of the rod outer segment discs. For the analysis of the measured diffraction pattern a new special computer procedure was elaborated. Among other generalizations of the theory, it was taken into account that the electron densities in the inter- and intra-disc spaces differ from the mean electron density of the whole stack. The consideration of this possibility, together with an exact experimental measurement of the isotrope background scattering, led to a mathematically unique solution. The calculated electron density profile apparently is a distinct asymmetric bilayer. The electron density of the side of the membrane which is in contact with the disc lumen is higher than the electron density on the side in contact with the cytoplasm. Therefore, a localization of rhodopsin or of other high molecular proteins mainly on the cytoplasmatic edge of the membrane can be excluded for the rod outer segment discs in vivo.
通过X射线小角散射研究了体内视杆外段盘膜的结构。实验是在麻醉状态下的青蛙身上进行的。从视杆外段盘的膜堆叠中可以获得对应于1.5纳米分辨率的衍射图样。为了分析测量的衍射图样，精心设计了一种新的特殊计算机程序。在该理论的其他推广中，考虑到盘间和盘内空间的电子密度与整个堆叠的平均电子密度不同。考虑到这种可能性，再加上对视向同性背景散射的精确实验测量，得出了一个数学上唯一的解。计算出的电子密度分布图显然是一个明显的不对称双层结构。与盘腔接触的膜面的电子密度高于与细胞质接触的膜面的电子密度。因此，对于体内视杆外段盘来说，可以排除视紫红质或其他高分子蛋白质主要定位于膜的细胞质边缘的可能性。
