Department of Mathematical and Physical Sciences, School of Engineering, Computing and Mathematical Sciences, La Trobe University, Melbourne, VIC, 3086, Australia.
La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
Nat Commun. 2022 Aug 11;13(1):4708. doi: 10.1038/s41467-022-32434-6.
The European X-ray Free Electron Laser (XFEL) and Linac Coherent Light Source (LCLS) II are extremely intense sources of X-rays capable of generating Serial Femtosecond Crystallography (SFX) data at megahertz (MHz) repetition rates. Previous work has shown that it is possible to use consecutive X-ray pulses to collect diffraction patterns from individual crystals. Here, we exploit the MHz pulse structure of the European XFEL to obtain two complete datasets from the same lysozyme crystal, first hit and the second hit, before it exits the beam. The two datasets, separated by <1 µs, yield up to 2.1 Å resolution structures. Comparisons between the two structures reveal no indications of radiation damage or significant changes within the active site, consistent with the calculated dose estimates. This demonstrates MHz SFX can be used as a tool for tracking sub-microsecond structural changes in individual single crystals, a technique we refer to as multi-hit SFX.
欧洲 X 射线自由电子激光（XFEL）和相干光源直线加速器（LCLS）II 是强度极高的 X 射线源，能够以兆赫兹（MHz）重复率产生连续毫微微秒晶体学（SFX）数据。之前的工作表明，利用连续的 X 射线脉冲可以从单个晶体中收集衍射图案。在这里，我们利用欧洲 XFEL 的 MHz 脉冲结构，在同一溶菌酶晶体离开光束之前，从第一次命中和第二次命中获得两个完整的数据集。这两个数据集相隔<1µs，可获得高达 2.1Å分辨率的结构。对两个结构的比较没有显示出任何辐射损伤或活性部位明显变化的迹象，与计算的剂量估计相符。这表明 MHz SFX 可以用作跟踪单个单晶中亚微秒结构变化的工具，我们称之为多命中 SFX。
