美国威斯康辛大学密尔沃基分校Marius Schmidt课题组，探究了如何利用欧洲X射线自由电子激光设备（ EuXFEL），在不同时间分辨飞秒研究晶体学。相关论文2019年11月18日在线发表在国际学术期刊《自然—方法学》上。

研究人员演示了如何在EuXFEL上以超快速度进行生物反应。研究人员利用MHz X射线脉冲速率研究光敏黄色蛋白（PYP）在光周期中的皮秒时间范围。研究表明可以获得高质量的差异电子密度图。该实验将先前探索的飞秒PYP动力学与同步加速器可访问的时标联系起来。这为EuXFEL在广泛时间分辨率的研究应用打开了大门。

研究人员表示，EuXFE是一个3.4公里长的X射线源，它以兆赫（MHz）重复频率产生极高强度的飞秒和空间相干的X射线脉冲。该X射线源经过精心设计，能够以近原子的空间分辨率观察超快过程。生物大分子的时间分辨晶体学是探索这些分子基本和功能性结构位移的基础。由于EuXFEL具有异常的MHz X射线脉冲结构，因此这些实验仍具有挑战性。

附：英文原文

Title: Time-resolved serial femtosecond crystallography at the European XFEL

Author: Suraj Pandey, Richard Bean, Tokushi Sato, Ishwor Poudyal, Johan Bielecki, Jorvani Cruz Villarreal, Oleksandr Yefanov, Valerio Mariani, Thomas A. White, Christopher Kupitz, Mark Hunter, Mohamed H. Abdellatif, Saa Bajt, Valerii Bondar, Austin Echelmeier, Diandra Doppler, Moritz Emons, Matthias Frank, Raimund Fromme, Yaroslav Gevorkov, Gabriele Giovanetti, Man Jiang, Daihyun Kim, Yoonhee Kim, Henry Kirkwood, Anna Klimovskaia, Juraj Knoska, Faisal H. M. Koua, Romain Letrun, Stella Lisova, Luis Maia, Victoria Mazalova, Domingo Meza, Thomas Michelat, Abbas Ourmazd, Guido Palmer, Marco Ramilli, Robin Schubert, Peter Schwander, Alessandro Silenzi, Jolanta Sztuk-Dambietz, Alexandra Tolstikova, Henry N. Chapman, Alexandra Ros, Anton Barty, Petra Fromme, Adrian P. Mancuso, Marius Schmidt

Issue&Volume: 2019-11-18

Abstract: The European XFEL (EuXFEL) is a 3.4-km long X-ray source, which produces femtosecond, ultrabrilliant and spatially coherent X-ray pulses at megahertz (MHz) repetition rates. This X-ray source has been designed to enable the observation of ultrafast processes with near-atomic spatial resolution. Time-resolved crystallographic investigations on biological macromolecules belong to an important class of experiments that explore fundamental and functional structural displacements in these molecules. Due to the unusual MHz X-ray pulse structure at the EuXFEL, these experiments are challenging. Here, we demonstrate how a biological reaction can be followed on ultrafast timescales at the EuXFEL. We investigate the picosecond time range in the photocycle of photoactive yellow protein (PYP) with MHz X-ray pulse rates. We show that difference electron density maps of excellent quality can be obtained. The results connect the previously explored femtosecond PYP dynamics to timescales accessible at synchrotrons. This opens the door to a wide range of time-resolved studies at the EuXFEL.

DOI: 10.1038/s41592-019-0628-z

Source: https://www.nature.com/articles/s41592-019-0628-z