论文标题

贝叶斯对球状蛋白的静态光散射数据的分析

Bayesian Analysis of Static Light Scattering Data for Globular Proteins

论文作者

Yin, Fan, Khago, Domarin, Martin, Rachel W., Butts, Carter T.

论文摘要

静态光散射是一种流行的物理化学技术,可以计算物理属性,例如回旋半径和第二个大分子(例如聚合物或蛋白质)的第二个病毒系数。第二个病毒系数是一种物理量,表征了颗粒之间成对相互作用的大小和迹象,因此与聚集倾向有关,这是一个相当大的科学和实践兴趣的特性。由于所需的精度和所涉及的误差结构的复杂性,从实验数据中估算第二个病毒系数是有挑战性的。与基于启发式OLS估计值的常规方法相反,贝叶斯对第二个病毒系数的推断允许明确建模误差过程,合并先验信息以及直接测试竞争物理模型的能力。在这里,我们介绍了一个全贝叶斯模型,用于在天颗粒系统上进行静态光散射实验,并具有浓度,折射率,低聚物大小和第二个病毒系数的关节推断。我们使用我们提出的模型来研究使用内部实验数据的鸡蛋白溶菌酶和人γ-晶状体的聚集行为。基于这些观察结果,我们还对这个实验家族中不确定性的主要驱动因素进行了模拟研究,特别表明了改善监测和控制浓度以帮助推理的潜力。

Static light scattering is a popular physical chemistry technique that enables calculation of physical attributes such as the radius of gyration and the second virial coefficient for a macromolecule (e.g., a polymer or a protein) in solution. The second virial coefficient is a physical quantity that characterizes the magnitude and sign of pairwise interactions between particles, and hence is related to aggregation propensity, a property of considerable scientific and practical interest. Estimating the second virial coefficient from experimental data is challenging due both to the degree of precision required and the complexity of the error structure involved. In contrast to conventional approaches based on heuristic OLS estimates, Bayesian inference for the second virial coefficient allows explicit modeling of error processes, incorporation of prior information, and the ability to directly test competing physical models. Here, we introduce a fully Bayesian model for static light scattering experiments on small-particle systems, with joint inference for concentration, index of refraction, oligomer size, and the second virial coefficient. We apply our proposed model to study the aggregation behavior of hen egg-white lysozyme and human gammaS-crystallin using in-house experimental data. Based on these observations, we also perform a simulation study on the primary drivers of uncertainty in this family of experiments, showing in particular the potential for improved monitoring and control of concentration to aid inference.

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