Low-dose X-ray structure analysis of cytochrome c oxidase utilizing high-energy X-rays.
Low-dose X-ray structure analysis of cytochrome c oxidase utilizing high-energy X-rays.
复制标题
利用高能 X 射线对细胞色素 c 氧化酶进行低剂量 X 射线结构分析。
DOI：
10.1107/s1600577519006805
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
M. Yamamoto.
中科院分区：
文献类型：
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作者：
G. Ueno;A. Shimada;E. Yamashita;K. Hasegawa;T. Kumasaka;K. Shinzawa-Itoh;S. Yoshikawa;T. Tsukihara;M. Yamamoto.
为了研究高能 X 射线对特定位点辐射损伤的影响，从金属酶细胞色素 C 氧化酶的辐射敏感晶体中收集了低剂量衍射数据。使用 30 keV X 射线和配备碲化镉传感器的高灵敏度像素阵列探测器在 SPring-8 的结构生物学 I 光束线 (BL41XU) 收集数据。使用多个晶体进行连续样品平移的实验装置使每个数据集的平均衍射加权剂量降低至 58 kGy，所得数据揭示了配体结构，其键长与使用 X 射线自由电子激光确定的无损伤结构中的键长相同。然而，对同步加速器数据精炼的配体结构周围残余密度的精确分析表明，可能存在小程度的特定损伤，这可能是由每个数据集 58 kGy 的累积剂量造成的。使用在线光谱仪在 10 至 30keV 的各种能量下对特定损伤的光子能量依赖性进行了进一步研究，通过紫外可见吸收光谱的变化进行评估。没有发现任何证据表明特定的辐射损伤与能量有关。
To investigate the effect of high-energy X-rays on site-specific radiation-damage, low-dose diffraction data were collected from radiation-sensitive crystals of the metal enzyme cytochrome c oxidase. Data were collected at the Structural Biology I beamline (BL41XU) at SPring-8, using 30 keV X-rays and a highly sensitive pixel array detector equipped with a cadmium telluride sensor. The experimental setup of continuous sample translation using multiple crystals allowed the average diffraction weighted dose per data set to be reduced to 58 kGy, and the resulting data revealed a ligand structure featuring an identical bond length to that in the damage-free structure determined using an X-ray free-electron laser. However, precise analysis of the residual density around the ligand structure refined with the synchrotron data showed the possibility of a small level of specific damage, which might have resulted from the accumulated dose of 58 kGy per data set. Further investigation of the photon-energy dependence of specific damage, as assessed by variations in UV-vis absorption spectra, was conducted using an on-line spectrometer at various energies ranging from 10 to 30 keV. No evidence was found for specific radiation damage being energy dependent.