Kubo Minoru, Nango Eriko, Tono Kensuke, Kimura Tetsunari, Owada Shigeki, Song Changyong, Mafuné Fumitaka, Miyajima Ken, Takeda Yoshihiro, Kohno Jun Ya, Miyauchi Naoya, Nakane Takanori, Tanaka Tomoyuki, Nomura Takashi, Davidsson Jan, Tanaka Rie, Murata Michio, Kameshima Takashi, Hatsui Takaki, Joti Yasumasa, Neutze Richard, Yabashi Makina, Iwata So
RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan.
J Synchrotron Radiat. 2017 Sep 1;24(Pt 5):1086-1091. doi: 10.1107/S160057751701030X. Epub 2017 Aug 22.
X-ray free-electron lasers (XFELs) have opened new opportunities for time-resolved X-ray crystallography. Here a nanosecond optical-pump XFEL-probe device developed for time-resolved serial femtosecond crystallography (TR-SFX) studies of photo-induced reactions in proteins at the SPring-8 Angstrom Compact free-electron LAser (SACLA) is reported. The optical-fiber-based system is a good choice for a quick setup in a limited beam time and allows pump illumination from two directions to achieve high excitation efficiency of protein microcrystals. Two types of injectors are used: one for extruding highly viscous samples such as lipidic cubic phase (LCP) and the other for pulsed liquid droplets. Under standard sample flow conditions from the viscous-sample injector, delay times from nanoseconds to tens of milliseconds are accessible, typical time scales required to study large protein conformational changes. A first demonstration of a TR-SFX experiment on bacteriorhodopsin in bicelle using a setup with a droplet-type injector is also presented.
X射线自由电子激光（XFEL）为时间分辨X射线晶体学带来了新机遇。本文报道了一种为在SPring-8埃紧凑型自由电子激光装置（SACLA）上对蛋白质中的光诱导反应进行时间分辨串行飞秒晶体学（TR-SFX）研究而开发的纳秒级光泵浦-XFEL探测装置。基于光纤的系统是在有限束流时间内快速搭建装置的理想选择，并且允许从两个方向进行泵浦照明，以实现蛋白质微晶的高激发效率。使用了两种类型的注射器：一种用于挤出高粘性样品，如脂质立方相（LCP），另一种用于脉冲液滴。在来自粘性样品注射器的标准样品流动条件下，可以获得从纳秒到几十毫秒的延迟时间，这是研究大蛋白质构象变化所需的典型时间尺度。本文还展示了使用带有液滴型注射器的装置对双分子层中的细菌视紫红质进行TR-SFX实验的首次演示。
