Predicting data quality in biological X-ray solution scattering
Predicting data quality in biological X-ray solution scattering
复制标题
预测生物 X 射线溶液散射的数据质量
DOI：
10.1107/s2059798318005004
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Gillilan, Richard E.
中科院分区：
文献类型：
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作者：
Wang, Chenzheng;Lin, Yuexia;Bougie, Devin;Gillilan, Richard E.
生物小角X射线溶液散射（BioSAXS）现在被广泛用于获得溶液状态下生物分子的信息。然而，通常情况下，事先并不清楚特定样品是否会分散得足够强，以提供有用的数据，从而在实际可实现的解决方案条件下得出结论。看起来很大的构象变化可能并不总是产生在实际浓度和暴露时间下彼此可区分的散射曲线。诸如时间分辨SAXS（TR-SAXS）的新兴技术由于小光束和短样品路径长度而带来额外的挑战。光束线光学在亮度和背景散射程度上各不相同，对光源的重大升级和改进有望扩大这些方法的范围。计算开发，以估计BioSAXS样品强度在一个更详细的水平比以前的方法，考虑到通量，能量，样品厚度，窗口材料，仪器背景，检测器效率，解决方案条件和其他参数。结果进行了验证与校准实验，使用标准蛋白质在四个不同的光束线与各种通量，能量和配置。BioSAXS在连续流时间分辨条件下统计区分各种构象运动的能力，然后在从大分子运动数据库（https：//www.example.com）中提取的一组匹配结构对上进行计算。molmovdb.org实验的可行性根据样本消耗进行排名，样本消耗是一个数量级的变化超过两个数量级的结构集。除了光子通量，计算表明，窗口散射和波长的选择也是重要的因素，因为在这种设置中常见的样品路径长度很短。
Biological small-angle X-ray solution scattering (BioSAXS) is now widely used to gain information on biomolecules in the solution state. Often, however, it is not obvious in advance whether a particular sample will scatter strongly enough to give useful data to draw conclusions under practically achievable solution conditions. Conformational changes that appear to be large may not always produce scattering curves that are distinguishable from each other at realistic concentrations and exposure times. Emerging technologies such as time-resolved SAXS (TR-SAXS) pose additional challenges owing to small beams and short sample path lengths. Beamline optics vary in brilliance and degree of background scatter, and major upgrades and improvements to sources promise to expand the reach of these methods. Computations are developed to estimate BioSAXS sample intensity at a more detailed level than previous approaches, taking into account flux, energy, sample thickness, window material, instrumental background, detector efficiency, solution conditions and other parameters. The results are validated with calibrated experiments using standard proteins on four different beamlines with various fluxes, energies and configurations. The ability of BioSAXS to statistically distinguish a variety of conformational movements under continuous-flow time-resolved conditions is then computed on a set of matched structure pairs drawn from the Database of Macromolecular Motions (https://molmovdb.org). The feasibility of experiments is ranked according to sample consumption, a quantity that varies by over two orders of magnitude for the set of structures. In addition to photon flux, the calculations suggest that window scattering and choice of wavelength are also important factors given the short sample path lengths common in such setups.