Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Am Chem Soc. 2010 Nov 10;132(44):15484-6. doi: 10.1021/ja106173n.
A new procedure, AXES, is introduced for fitting small-angle X-ray scattering (SAXS) data to macromolecular structures and ensembles of structures. By using explicit water models to account for the effect of solvent, and by restricting the adjustable fitting parameters to those that dominate experimental uncertainties, including sample/buffer rescaling, detector dark current, and, within a narrow range, hydration layer density, superior fits between experimental high resolution structures and SAXS data are obtained. AXES results are found to be more discriminating than standard Crysol fitting of SAXS data when evaluating poorly or incorrectly modeled protein structures. AXES results for ensembles of structures previously generated for ubiquitin show improved fits over fitting of the individual members of these ensembles, indicating these ensembles capture the dynamic behavior of proteins in solution.
一种新的方法 AXES 被引入，用于将小角度 X 射线散射（SAXS）数据拟合到大分子结构和结构的集合中。通过使用显式的水分子模型来解释溶剂的影响，并将可调节的拟合参数限制为那些主导实验不确定性的参数，包括样品/缓冲液的重新缩放、探测器暗电流，以及在狭窄范围内，水合层密度，从而获得实验高分辨率结构和 SAXS 数据之间更好的拟合。在评估建模不良或不正确的蛋白质结构时，AXES 的结果比标准的 Crysol 对 SAXS 数据的拟合更具辨别力。对于先前为泛素生成的结构集合的 AXES 结果显示出比这些集合的各个成员的拟合更好的拟合，这表明这些集合捕获了蛋白质在溶液中的动态行为。
