A procedure to analyze surface profiles of the protein molecules visualized by quick-freeze deep-etch replica electron microscopy
A procedure to analyze surface profiles of the protein molecules visualized by quick-freeze deep-etch replica electron microscopy
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DOI：
10.1016/j.ultramic.2006.04.012
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发表时间：
2007-01-01
期刊：
影响因子：
2.2
通讯作者：
Katayama, Eisaku
中科院分区：
文献类型：
--
作者：
Kimori, Yoshitaka;Oguchi, Yosuke;Katayama, Eisaku
速冻深蚀刻复制电子显微镜在体外或原位生理条件下提供单个蛋白质分子的高对比度快照。这些图像显示了精细的内部图案，可能反映了分子的旋转阴影表面轮廓。作为建立“单分子结构分析”新系统的一步，我们提出了一个定量表征单个分子结构特性的程序;例如，如果目标分子的晶体结构可用，分子的构象类型和精确视角。本文提出了一个框架，以确定所观察到的蛋白质分子的表面分析的冷冻复制标本中可视化的单个分子的表面轮廓。使用光渲染软件从可用的原子坐标中人工生成了一组全面的蛋白质分子旋转阴影视图。利用新的数学形态学图像滤波器，从每幅图像中提取特征并存储为模板。从真实的复制品图像中提取相似的特征，并通过与一组存档图像的定量比较来确定观察到的颗粒的最可能的投影角度和构象。在实际应用的定义配置中，使用肌球蛋白头结构检查了该程序的性能和稳健性。(c)2006 Elsevier B. V.保留所有权利。
Quick-freeze deep-etch replica electron microscopy gives high contrast snapshots of individual protein molecules under physiological conditions in vitro or in situ. The images show delicate internal pattern, possibly reflecting the rotary-shadowed surface profile of the molecule. As a step to build the new system for the "Structural analysis of single molecules", we propose a procedure to quantitatively characterize the structural property of individual molecules; e.g. conformational type and precise view-angle of the molecules, if the crystallographic structure of the target molecule is available. This paper presents a framework to determine the observed face of the protein molecule by analyzing the surface profile of individual molecules visualized in freeze-replica specimens. A comprehensive set of rotary-shadowed views of the protein molecule was artificially generated from the available atomic coordinates using light-rendering software. Exploiting new mathematical morphology-based image filter, characteristic features were extracted from each image and stored as template. Similar features were extracted from the true replica image and the most likely projection angle and the conformation of the observed particle were determined by quantitative comparison with a set of archived images. The performance and the robustness of the procedure were examined with myosin head structure in defined configuration for actual application. (c) 2006 Elsevier B.V. All rights reserved.