通过冷STEM断层扫描揭示的费里丁结晶的机制
Lothar Houben1, Haim Weissman2, Sharon G Wolf3
1Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel. lothar.houben@weizmann.ac.il.
Nature
|March 28, 2020
概括
非经典的蛋白质结晶涉及无形前体,而不是经典的核化. 低温电子显微镜揭示了由溶解驱动的费里聚合物的逐渐排序,挑战了现有的核化理论.
科学领域:
- 结构生物学
- 生物物理
- 材料科学
背景情况:
- 蛋白质结晶对于结构生物学,疾病研究和制药至关重要.
- 非经典结晶,涉及无形前体,是常见的,但其分子机制仍然不清楚.
- 经典核化理论假定核的密度与最终的晶体相同,不同于观察到的非经典路径.
研究的目的:
- 阐明非经典蛋白质结晶的分子机制.
- 确定无形前体的性质以及它们中的分子秩序.
- 提供蛋白质结晶过程的分子级成像.
主要方法:
- 使用冷扫描传输电子显微镜断层成像来绘制费里聚合物.
- 使用同步代重建技术进行了三维 (3D) 重建.
- 分析的重点是聚合物在各种结晶阶段的秩序和密度的演变.
主要成果:
- 从表面到内部的费里聚合物的顺序和密度逐渐增加.
- 没有发现古典核形成的小,高度有序结构的证据.
- 在单个无形聚合物中出现的多个有序域,这是当前理论没有预测的现象.
结论:
- 非经典的蛋白质结晶是通过一个连续的顺序进化机制进行的,这种机制可能是由溶解驱动的.
- 这些发现挑战了古典和两步核化理论.
- 观察到的机制为蛋白质结晶途径提供了更广泛的视角.
相关概念视频
01:28Cryo-electron Microscopy
4.1K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
4.1K
01:07Electron Microscope Tomography and Single-particle Reconstruction
2.7K
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
2.7K