X-ray diffraction analysis of wet isolated bovine rod outer segment disks. A dehydration study.
X-ray diffraction analysis of wet isolated bovine rod outer segment disks. A dehydration study.
复制标题
湿分离牛杆外节盘的 X 射线衍射分析。
DOI：
10.1016/0005-2736(82)90322-4
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
G. Reynolds
中科院分区：
文献类型：
--
作者：
S. Gruner;D. T. Barry;G. Reynolds
X 射线衍射图案序列是从脱水的、人工定向的分离的牛杆外节盘多层中获得的。对高度水合的样品进行直接相分析，以确定脱水过程中圆盘的低分辨率（约 30 Å）电子密度分布序列。人们发现，随着多层晶格同时收缩并变得越来越有序，轮廓会平稳地演变。双层轮廓在脱水情况下基本保持不变，并且衍射的演变与流体间距的简单减小一致。当多层变得过于脱水时，观察到样品相分离成特征性的初级晶格和次级晶格。次级晶格的小晶胞尺寸表明存在脂质相。在样品漂白时，观察到相分离样品的衍射图案发生很大变化。这些变化与主晶格的可逆无序一致。
Sequences of X-ray diffraction patterns were obtained from dehydrating, artificially oriented multilayers of isolated, bovine rod outer segment disks. A direct-phase analysis was applied to highly hydrated specimens to determine sequences of low resolution (approx. 30 Å) electron density profiles of the disks as dehydration proceeded. The profiles were found to evolve smoothly as the multilayer lattice simultaneously shrank and became increasingly ordered. The bilayer profiles were largely invariant under dehydration and the evolution of the diffraction consistent with simple decreases in fluid spacings. The specimens were observed to phase separate into characteristic primary and a secondary lattices when the multi-layer became too dehydrated. The small unit cell size of the secondary lattice was suggestive of a lipid phase. Large changes in the diffraction patterns from phase separated specimens were observed upon bleaching of the specimen. The changes were consistent with a reversible disordering of the primary lattice.