Coughlan H D, Darmanin C, Kirkwood H J, Phillips N W, Hoxley D, Clark J N, Vine D J, Hofmann F, Harder R J, Maxey E, Abbey B
ARC Centre of Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia.
Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.
J Synchrotron Radiat. 2017 Jan 1;24(Pt 1):83-94. doi: 10.1107/S1600577516017525.
The proliferation of extremely intense synchrotron sources has enabled ever higher-resolution structures to be obtained using data collected from smaller and often more imperfect biological crystals (Helliwell, 1984). Synchrotron beamlines now exist that are capable of measuring data from single crystals that are just a few micrometres in size. This provides renewed motivation to study and understand the radiation damage behaviour of small protein crystals. Reciprocal-space mapping and Bragg coherent diffractive imaging experiments have been performed on cryo-cooled microcrystals of hen egg-white lysozyme as they undergo radiation damage. Several well established metrics, such as intensity-loss and lattice expansion, are applied to the diffraction data and the results are compared with several new metrics that can be extracted from the coherent imaging experiments. Individually some of these metrics are inconclusive. However, combining metrics, the results suggest that radiation damage behaviour in protein micro-crystals differs from that of larger protein crystals and may allow them to continue to diffract for longer. A possible mechanism to account for these observations is proposed.
极其强大的同步加速器光源的不断增加，使得利用从小的、通常更不完善的生物晶体收集的数据获得分辨率越来越高的结构成为可能（赫利韦尔，1984年）。现在存在能够测量尺寸仅为几微米的单晶数据的同步加速器光束线。这为研究和理解小蛋白质晶体的辐射损伤行为提供了新的动力。在冷冻冷却的鸡蛋清溶菌酶微晶遭受辐射损伤时，进行了倒易空间映射和布拉格相干衍射成像实验。将几个成熟的指标，如强度损失和晶格膨胀，应用于衍射数据，并将结果与几个可从相干成像实验中提取的新指标进行比较。单独来看，其中一些指标并无定论。然而，综合各项指标，结果表明蛋白质微晶中的辐射损伤行为与较大蛋白质晶体的不同，并且可能使它们能够继续衍射更长时间。提出了一种解释这些观察结果的可能机制。
