Quantitative, Mechanistic Studies of Biomolecular Recognition

项目总结 生物学正在经历一场革命，生物分子凝聚体在很大程度上颠覆了我们的理解 分子、细胞和发育生物学。这些通过相分离形成的冷凝物 至关重要的细胞功能，并与神经退行性变和癌症有关。然而，我们才刚刚开始获得 对生物分子凝聚物的性质和复杂行为的物理理解一瞥。A Main 该项目的目标是弥合相变生物学和物理学之间不断扩大的理解鸿沟。 分离。在前一个资助期奠定的坚实基础上，我们将整合理论， 解决微尺度解释中的巨大挑战的计算和实验方法 关于组成大分子的构象和相互作用的生物现象。 要解决的问题包括：(1)计算点突变和翻译后的影响 相平衡的修正；(2)凝析油中非特定相互作用的量化；(3)测量 凝析油的分子和材料性质；(4)凝析油老化的模拟。面临的一些挑战 产生于驱动相分离的大分子中普遍存在的内在无序区域。 因此，我们将对本质上的构象和动力学性质进行全面的研究 与伴侣形成特定复合体时的无序蛋白质及其途径。而后者则是具体的， 双分子相互作用代表了分子识别的传统范例，相分离定义了 分子识别在微观尺度上的范例，由弱的、非特异性的相互作用和 分子的集合。分子识别的第三个范例是蛋白质与 膜，其中结合蛋白的构象和姿势以及近端脂质的组成 都是高度动态的。我们将深入探讨WASP和突触素的半特异性联系 酸性膜填补其作用机制中的关键空白。计划中的研究不仅将 促进对生物学的基本理解，但也为设计治疗方法提供新的机会。

PROJECT SUMMARY Biology is undergoing a revolution, where biomolecular condensates are upending our understanding in much of molecular, cell, and developmental biology. These condensates, formed through phase separation, mediate crucial cellular functions and are linked with neurodegeneration and cancer. Yet we are only starting to gain a glimpse of physical understanding of the properties and complex behaviors of biomolecular condensates. A main goal of this project is to bridge the widening gap in understanding between the biology and physics of phase separation. Building on the strong foundations laid in the previous funding period, we will integrate theoretical, computational, and experimental approaches to tackle the enormous challenges in interpreting microscale biological phenomena in terms of the conformations and interactions of the constituent macromolecules. Questions to be addressed include: (1) computing the effects of point mutations and posttranslational modifications on phase equilibrium; (2) quantifying nonspecific interactions in condensates; (3) measuring molecular and material properties of condensates; and (4) modeling condensate aging. Some of the challenges arise from intrinsically disordered regions ubiquitously present in macromolecules that drive phase separation. We will therefore carry out comprehensive studies into the conformational and dynamic properties of intrinsically disordered proteins and their pathways when forming specific complexes with partners. While the latter specific, bimolecular interactions represent the traditional paradigm of molecular recognition, phase separation defines a paradigm of molecular recognition at the microscale, mediated by weak, nonspecific interactions among an ensemble of molecules. A third paradigm of molecular recognition is semi-specific association of proteins with membranes, where the conformation and pose of the bound protein and the composition of the proximal lipids are all highly dynamic. We will deeply probe the semi-specific association of WASP and synaptogamins with acidic membranes to fill in critical gaps in their functional mechanisms. The planned research will not only advance fundamental understanding in biology but also yield new opportunities for designing therapies.