Falke S, Fisher M T, Gogol E P
Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
J Struct Biol. 2001 Feb-Mar;133(2-3):203-13. doi: 10.1006/jsbi.2001.4354.
Image analysis methods were used to separate images of a large macromolecular complex, the chaperonin GroEL, in a preparation in which it is partially liganded to a nonnative protein substrate, glutamine synthetase. The relatively small difference ( approximately 6%) in size between the chaperonin in its free and complexed forms, and the absence of gross changes in overall conformation, made separation of the two types of particles challenging. Different approaches were evaluated and used for alignment and classification of images, both in two common projections and in three dimensions, yielding 2D averages and a 3D reconstruction. The results of 3D analysis describe the conformational changes effected by binding of this particular protein substrate and demonstrate the utility of 2D analysis as an indicator of structural change in this system.
图像分析方法被用于分离一种大型大分子复合物——伴侣蛋白GroEL的图像，该复合物存在于一种制剂中，在这种制剂中它部分地与一种非天然蛋白质底物谷氨酰胺合成酶结合。伴侣蛋白的游离形式和复合形式在大小上相对较小的差异（约6%）以及整体构象没有明显变化，使得分离这两种类型的颗粒具有挑战性。对不同的方法进行了评估，并用于二维常见投影和三维图像的对齐和分类，得到了二维平均值和三维重建。三维分析结果描述了这种特定蛋白质底物结合所引起的构象变化，并证明了二维分析作为该系统结构变化指标的实用性。
