McPherson A, Malkin A J
Department of Molecular Biology and Biochemistry, University of California, Irvine 92697-3900, USA.
Annu Rev Biophys Biomol Struct. 2000;29:361-410. doi: 10.1146/annurev.biophys.29.1.361.
Atomic force microscopy (AFM) has been used to study protein, nucleic acid, and virus crystals in situ, in their mother liquors, as they grow. From sequential AFM images taken at brief intervals over many hours, or even days, the mechanisms and kinetics of the growth process can be defined. The appearance of both two- and three-dimensional nuclei on crystal surfaces have been visualized, defect structures of crystals were clearly evident, and defect densities of crystals were also determined. The incorporation of a wide range of impurities, ranging in size from molecules to microns or larger microcrystals, and even foreign particles were visually recorded. From these observations and measurements, a more complex understanding of the detailed character of macromolecular crystals is emerging, one that reveals levels of complexity previously unsuspected. The unique features of these crystals, apparently in AFM images, undoubtedly influence the diffraction properties of the crystals and the quality of the molecular images obtained by X-ray crystallography.
原子力显微镜（AFM）已被用于原位研究蛋白质、核酸和病毒晶体，即在其母液中生长时的情况。通过在数小时甚至数天内以短时间间隔拍摄的连续AFM图像，可以确定生长过程的机制和动力学。晶体表面二维和三维核的出现已被可视化，晶体的缺陷结构清晰可见，晶体的缺陷密度也已确定。从分子到微米或更大的微晶甚至外来颗粒等各种杂质的掺入情况都被直观地记录下来。基于这些观察和测量，人们对大分子晶体的详细特征有了更复杂的认识，这种认识揭示了以前未被怀疑的复杂程度。这些晶体在AFM图像中的独特特征无疑会影响晶体的衍射特性以及通过X射线晶体学获得的分子图像的质量。
