Glaeser R M, Jubb J S, Henderson R
Biophys J. 1985 Nov;48(5):775-80. doi: 10.1016/S0006-3495(85)83835-2.
Lipid-depleted purple membrane prepared by extraction with deoxycholate has been compared with the native structure. X-ray and electron diffraction photographs show a reduction in cell dimension from 62.4 to 57.3 A, and a substantial change in the distribution of diffraction intensity compared with the native specimens. Low-dose electron microscopy has been used to obtain a projected density map of lipid-depleted membranes. The projected structure shows that the deoxycholate treatment removes a boundary layer of lipid, which in the native form separates adjacent trimers of bacteriorhodopsin. The map also provides an improved estimate of the molecular envelope of the protein. A plausible arrangement for the lipid molecules in both the native and the lipid-depleted membranes is proposed, but the precise positions of individual molecules cannot yet be specified.
用脱氧胆酸盐提取制备的脱脂紫膜已与天然结构进行了比较。X射线和电子衍射照片显示，细胞尺寸从62.4埃减小到57.3埃，与天然标本相比，衍射强度分布发生了显著变化。低剂量电子显微镜已被用于获得脱脂膜的投影密度图。投影结构表明，脱氧胆酸盐处理去除了一层脂质边界层，在天然形式下，该边界层将相邻的细菌视紫红质三聚体分隔开。该图还提供了对蛋白质分子包膜的改进估计。提出了天然膜和脱脂膜中脂质分子的一种合理排列方式，但单个分子的精确位置尚无法确定。
