Lomakin Aleksey, Teplow David B, Benedek George B
Department of Physics and Center for Materials Sciences and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
Methods Mol Biol. 2005;299:153-74. doi: 10.1385/1-59259-874-9:153.
Quasielastic light scattering (QLS) spectroscopy is an optical method for the determination of diffusion coefficients of particles in solution. In this chapter, we discuss the principles and practice of QLS with respect to protein assembly reactions. Particles undergoing Brownian motion produce fluctuations in scattered light intensity. We describe how the temporal correlation function of these fluctuations can be measured and how this correlation function provides information about the distribution of diffusion coefficients of the particles in solution. We discuss the intricacies of deconvolution of the correlation function and the assumptions incorporated into data analysis procedures. We explain how the Stokes-Einstein relationship can be used to convert distributions of diffusion coefficients into distributions of particle size. Noninvasive observation of the temporal evolution of particles sizes provides a powerful tool for studying protein aggregation and self-assembly. We use examples from studies of Abeta fibrillogenesis to illustrate QLS application for understanding the molecular mechanisms of the nucleation and growth of amyloid fibrils.
准弹性光散射（QLS）光谱法是一种用于测定溶液中颗粒扩散系数的光学方法。在本章中，我们将讨论关于蛋白质组装反应的QLS原理及实践。经历布朗运动的颗粒会使散射光强度产生波动。我们将描述如何测量这些波动的时间相关函数，以及该相关函数如何提供有关溶液中颗粒扩散系数分布的信息。我们将讨论相关函数去卷积的复杂性以及数据分析程序中所包含的假设。我们将解释如何利用斯托克斯-爱因斯坦关系将扩散系数分布转换为颗粒尺寸分布。对颗粒尺寸随时间演变的非侵入性观察为研究蛋白质聚集和自组装提供了一个强大的工具。我们通过β-淀粉样蛋白纤维形成研究中的例子来说明QLS在理解淀粉样纤维成核和生长分子机制方面的应用。
