Multi-Method Approaches for the Study of Complex Protein Interactions

由于单一的生物物理技术在可观察的属性数量上是有限的，一个有前途的方法是同时考虑来自多个生物物理技术的数据。因此，一个重要的目标是开发一个健壮和通用的计算框架，用于对使用不同技术进行的三重(或更高)蛋白质混合物的结合研究进行全球分析。过去，我们为此开发了一个数据分析程序SEDPHAT，用于对沉积速度、沉积平衡、动态光散射、等温滴定量热法和表面结合等数据进行全局分析。它现在被广泛应用于生物物理界，用于蛋白质相互作用的数据分析。然而，对来自不同技术的数据进行联合分析仍然非常罕见，其全部潜力尚未被发掘。困难之一是，必须详细了解每种应用技术的局限性和系统误差。为此，我们对相互作用的蛋白质体系进行了实验，作为研究来自表面结合、量热、圆二色光谱和沉淀数据的详细兼容性的模型。我们继续努力通过结合沉淀法和光散射法来确定大分子复合体的详细尺寸和形状分布。

Since a single biophysical technique is limited in the number of observable properties, one promising approach is the simultaneous consideration of data from multiple biophysical techniques. Therefore, one important goal is develop a robust and general computational framework for the global analysis of binding studies of triple (or higher) protein mixtures conducted with different techniques. In the past, we have developed for this purpose a data analysis program SEDPHAT for the global analysis of data from sedimentation velocity, sedimentation equilibrium, dynamic light scattering, isothermal titration calorimetry, and surface binding. It is now widely used in the biophysical community for data analysis of protein interactions. However, the combined analysis of data from different techniques is still very rare, and the full potential has not yet been explored. One of the difficulties is that a detailed understanding of the limitations and systematic errors for each of the applied techniques is essential. To this end, we have conducted experiments with interacting protein systems to serve as model for the study of the detailed compatibility of data from surface binding, calorimetry, circular dichroism spectroscopy, and sedimentation. We have continued our efforts to determine detailed size-and-shape distributions of macromolecular complexes by combined sedimentation and light scattering approaches.