Reaching the Information Limit in Cryo-EM of Biological Macromolecules: Experimental Aspects
Reaching the Information Limit in Cryo-EM of Biological Macromolecules: Experimental Aspects
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DOI：
10.1016/j.bpj.2011.04.018
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发表时间：
2011-05-18
影响因子：
3.4
通讯作者：
Hall, Richard J.
中科院分区：
文献类型：
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作者：
Glaeser, Robert M.;Hall, Richard J.
尽管生物大分子的低温电子显微镜（cryo-EM）在过去几年中取得了重要进展，但目前的技术性能水平仍然远远低于电子散射物理所允许的水平。例如，使用低温电镜（cryo-EM）在原子分辨率下解决颗粒尺寸远低于80 kDa的蛋白质结构应该是可能的，但目前只能实现至少10倍大的颗粒。在本文中，我们首先研究造成这种巨大性能差距的一些原因。然后，我们概述了目前正在进行的工作：1)，提高区域检测器的信噪比；2)、提高散射电子与相应图像之间的信号传递；3)降低波束引起的移动在高分辨率下导致信号急剧下降的程度。在每种情况下，都有充分的理由认为冷冻电镜确实可以接近估计的物理极限。
Although cryo-electron microscopy (cryo-EM) of biological macromolecules has made important advances in the past few years, the level of current technical performance is still well below what the physics of electron scattering would allow. It should be possible, for example, to use cryo-EM to solve protein structures at atomic resolution for particle sizes well below 80 kDa, but currently this has been achieved only for particles at least 10 times larger than that. In this review, we first examine some of the reasons for this large gap in performance. We then give an overview of work that is currently in progress to 1), improve the signal/noise ratio for area detectors; 2), improve the signal transfer between the scattered electrons and the corresponding images; and 3), reduce the extent to which beam-induced movement causes a steep fall-off of signal at high resolution. In each case, there is substantial reason to think that cryo-EM can indeed be made to approach the estimated physical limits.