Potential for biomolecular imaging with femtosecond X-ray pulses
Potential for biomolecular imaging with femtosecond X-ray pulses
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DOI：
10.1038/35021099
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发表时间：
2000-08-17
期刊：
影响因子：
64.8
通讯作者：
Hajdu, J
中科院分区：
文献类型：
--
作者：
Neutze, R;Wouts, R;Hajdu, J
X射线和其他辐射造成的样品损伤限制了对非重复和不可再现结构（如单个生物分子或细胞）进行结构研究的分辨率（1）。冷却可以减缓样品劣化，但不能消除传统测量所需时间内由损伤引起的样品移动（1，2）。损伤形成的动力学分析（3-5）表明，常规损伤势垒（具有12 keV能量或1埃波长的X射线的每埃约200个X射线光子（2））可以在非常高的剂量率和非常短的曝光时间下扩展。在这里，我们使用计算机模拟来研究结构信息，可以从单个蛋白质分子和小组件的强烈飞秒X射线脉冲的散射中恢复。作为光子能量、脉冲长度、积分脉冲强度和样品大小的函数的辐射损伤的估计表明，使用非常高的X射线剂量率和超短曝光的实验可以在辐射损伤破坏样品之前提供有用的结构信息。我们预测，这种超短，高强度的X射线脉冲，从自由电子激光器（6，7），目前正在开发中，结合无容器的样品处理方法的基础上喷雾技术，将提供一种新的方法，结构测定与X射线。
Sample damage by X-rays and other radiation limits the resolution of structural studies on non-repetitive and non-reproducible structures such as individual biomolecules or cells(1). Cooling can slow sample deterioration, but cannot eliminate damage-induced sample movement during the time needed for conventional measurements(1,2). Analyses of the dynamics of damage formation(3-5) suggest that the conventional damage barrier (about 200 X-ray photons per Angstrom(2) with X-rays of 12 keV energy or 1 Angstrom wavelength 2) may be extended at very high dose rates and very short exposure times. Here we have used computer simulations to investigate the structural information that can be recovered from the scattering of intense femtosecond X-ray pulses by single protein molecules and small assemblies. Estimations of radiation damage as a function of photon energy, pulse length, integrated pulse intensity and sample size show that experiments using very high X-ray dose rates and ultrashort exposures may provide useful structural information before radiation damage destroys the sample. We predict that such ultrashort, high-intensity X-ray pulses from free-electron lasers(6,7) that are currently under development, in combination with container-free sample handling methods based on spraying techniques, will provide a new approach to structural determinations with X-rays.