LIPID LOCATION IN DEOXYCHOLATE-TREATED PURPLE MEMBRANE AT 2.6 ANGSTROM
LIPID LOCATION IN DEOXYCHOLATE-TREATED PURPLE MEMBRANE AT 2.6 ANGSTROM
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DOI：
10.1006/jmbi.1995.0627
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发表时间：
1995-12-01
影响因子：
5.6
通讯作者：
ZEMLIN, F
中科院分区：
文献类型：
--
作者：
GRIGORIEFF, N;BECKMANN, E;ZEMLIN, F
使用在液氦温度下操作的 200 keV FEG 显微镜，仅使用图像即可获得 2.6 埃的脱氧胆酸盐处理紫色膜的高分辨率投影。对这张高质量图的检查得出了以下结论：天然晶体形式和脱氧胆酸盐处理晶体形式的三聚体的内部结构之间的比较表明，高分辨率结构的几乎每个细节都是相同的。细胞尺寸从 62.4 埃变化到 57.9 埃，伴随着正常脂质约一半的损失以及作为刚体的三聚体逆时针旋转 2 度。每个细菌视紫红质分子的三个脂质相对于三聚体保持在相同的位置。此外，根据投影图以及使用细菌视紫红质原子模型的堆积分析，已经确定了另外三种脂质的空间，使得该晶体形式的每个细菌视紫红质分子总共有六种脂质。最后，具有完全不同范德华接触的两种晶体形式之间的三聚体的旋转令人惊讶地小，这表明晶体通过强的长程静电相互作用保持在一起。 (C) 1995 学术出版社有限公司
A high resolution projection at 2.6 Angstrom of deoxycholate-treated purple membrane using only images has been obtained with a 200 keV FEG microscope operated at liquid helium temperature. Examination of this high quality map has allowed the following conclusions to be made: Comparison between the internal structure of the trimers of the native and the deoxycholate-treated crystal forms shows that almost every detail of the structure at high resolution is identical. The cell dimension change from 62.4 Angstrom to 57.9 Angstrom is accompanied by a loss of about half the normal lipids and a 2 degrees anticlockwise rotation of the trimer as a rigid body. Three of the lipids per bacteriorhodopsin molecule remain in identical positions relative to the trimer. In addition, from the projection map together with a packing analysis using the atomic model for bacteriorhodopsin, space for three further lipids has been identified making a total of six lipids per bacteriorhodopsin molecule in this crystal form. Finally, the surprisingly small rotation of the trimer between the two crystal forms with completely different Van der Waals contacts suggest that the crystals are held together by strong, long-range electrostatic interactions. (C) 1995 Academic Press Limited