Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen E, Denmark.
Acta Crystallogr D Struct Biol. 2022 Apr 1;78(Pt 4):483-493. doi: 10.1107/S2059798322001838. Epub 2022 Mar 11.
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.
在线尺寸排阻色谱和小角 X 射线散射（SEC-SAXS）的组合正在迅速成为溶液中复杂生物物理样品结构研究的关键技术。本文概述了一种围绕该技术的新型模型修正策略，并通过分析磷脂双层纳米盘的几个 SEC-SAXS 实验系列的数据来证明其效用。使用该方法，可以针对同一数据系列中的多个帧对单个模型进行全局修正，从而捕获辐照样品的逐帧趋势。这些趋势与以传统方式进行的模型修正进行了比较，其中的修正基于同一数据系列中一组连续帧的平均轮廓，而没有对单个帧进行深入比较。这被认为是一种有吸引力的模型修正方案，因为它大大降低了从数据系列中精炼的总参数数量，产生了帧与帧之间自动一致的趋势，并利用了比此类实验中通常执行的更大一部分记录数据。此外，本文还概述了一种通过考虑实验装置潜在的峰展宽来校正测量的紫外吸收信号的方法。
