A method for establishing the handedness of biological macromolecules
A method for establishing the handedness of biological macromolecules
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DOI：
10.1006/jsbi.1997.3896
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发表时间：
1997-01-01
影响因子：
3
通讯作者：
Baker, TS
中科院分区：
文献类型：
--
作者：
Belnap, DM;Olson, NH;Baker, TS
当生物大分子在透射电子显微镜 (TEM) 中成像时，它们固有的旋向性会丢失，因为三维 (3D) 结构被投影到二维 (2D) 平面上，并且可以从任一 3D 对映体进行相同的 2D 投影。然而，TEM 中的倾斜实验可用于确定惯用手。这些实验已在负染色样本上成功进行。最近，该方法被应用于通过冷冻电子显微镜 (cryoTEM) 方法成像的未染色、冷冻水合样本。倾斜实验包括以不同倾斜角度记录相同颗粒的两张显微照片，根据一张显微照片中的颗粒图像计算对映体重建，预测第二张显微照片中相应颗粒的方向，以及将模型投影与第二张显微照片中的颗粒图像进行比较。原则上，只要对映体重建是可区分的，该程序可用于确定冷冻TEM成像的任何生物大分子的旋手性。 (C) 1997 年学术出版社。
When biological macromolecules are imaged in the transmission electron microscope (TEM), their inherent handedness is lost because the three-dimensional (3D) structure is projected onto a two-dimensional (2D) plane, and identical 2D projections can be made from either 3D enantiomer. Nevertheless, tilt experiments in the TEM can be used to determine handedness. These experiments have been performed successfully on negatively stained specimens. More recently, the method was applied to unstained, frozen-hydrated specimens imaged by means of cryoelectron microscopy (cryoTEM) methods. Tilt experiments involve recording two micrographs of the same particles at different tilt angles, computing enantiomeric reconstructions from particle images in one micrograph, predicting orientations of corresponding particles in the second micrograph, and comparing model projections with particle images in the second micrograph. In principle, this procedure can be used to determine the handedness of any biological macromolecule imaged by cryoTEM, provided the enantiomeric reconstructions are distinguishable. (C) 1997 Academic Press.