Global fitting of multiple data frames from SEC-SAXS to investigate the structure of next-generation nanodiscs.
Global fitting of multiple data frames from SEC-SAXS to investigate the structure of next-generation nanodiscs.
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从SEC-SAXS进行多个数据帧的全局拟合，以研究下一代纳米盘的结构。
DOI：
10.1107/s2059798322001838
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发表时间：
2022-04-01
期刊：
影响因子：
--
通讯作者：
Pedersen MC
中科院分区：
文献类型：
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作者：
Barclay A;Tidemand Johansen N;Tidemand FG;Arleth L;Pedersen MC
提出了一种从相同尺寸排阻色谱小角散射实验的多个数据框中提炼模型的框架。该方法可以大大减少从数据序列中提炼的参数数量。在线排粒径层析与小角度x射线散射（SEC-SAXS）相结合，正迅速成为精细生物物理样品结构研究的关键技术。本文概述了一种以该技术为中心的新型模型优化策略，并通过分析几个SEC-SAXS在磷脂双层纳米盘上的实验数据序列来证明其实用性。使用这种方法，单个模型针对来自同一数据系列的许多帧进行全局细化，从而捕获辐照样品的帧间趋势。将这些模型与传统方式的改进模型进行比较，传统方式的改进是基于同一数据系列中一组连续帧的平均轮廓，而不深入比较单个帧。这被认为是一种有吸引力的模型改进方案，因为它大大降低了从数据序列中改进的参数总数，产生了帧之间自动一致的趋势，并且利用了比此类实验中经常执行的记录数据的相当大的一部分。此外，还概述了一种通过计算实验装置的电位峰展宽来校正测量的紫外吸收信号的方法。
A framework is presented for refining models from several data frames from the same size-exclusion chromatography small-angle scattering experiment. The method can be employed to drastically reduce the number of parameters refined from the data series. The combination of online size-exclusion chromatography and small-angle X-ray scattering (SEC–SAXS) is rapidly becoming a key technique for structural investigations of elaborate biophysical samples in solution. Here, a novel model-refinement strategy centred around the technique is outlined and its utility is demonstrated by analysing data series from several SEC–SAXS experiments on phospholipid bilayer nanodiscs. Using this method, a single model was globally refined against many frames from the same data series, thereby capturing the frame-to-frame tendencies of the irradiated sample. These are compared with models refined in the traditional manner, in which refinement is based on the average profile of a set of consecutive frames from the same data series without an in-depth comparison of individual frames. This is considered to be an attractive model-refinement scheme as it considerably lowers the total number of parameters refined from the data series, produces tendencies that are automatically consistent between frames, and utilizes a considerably larger portion of the recorded data than is often performed in such experiments. Additionally, a method is outlined for correcting a measured UV absorption signal by accounting for potential peak broadening by the experimental setup.