Quantitative, Mechanistic Studies of Biomolecular Recognition

项目摘要 生物学正在经历一场革命，生物分子凝聚物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， 重要的细胞功能，并与神经变性和癌症有关。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的一瞥。主 这个项目的目标是弥合生物学和物理学之间日益扩大的理解差距， 分居在前一个资助期奠定的坚实基础上，我们将整合理论， 计算和实验方法来解决解释微观尺度的巨大挑战 生物现象的构象和相互作用的组成大分子。 要解决的问题包括：（1）计算点突变和翻译后效应 修正相平衡;（2）定量冷凝物中的非特异性相互作用;（3）测量 凝析油的分子和材料性质;和（4）模拟凝析油老化。的一些挑战 由普遍存在于大分子中的驱动相分离的固有无序区域产生。 因此，我们将开展全面的研究，以构象和动力学性质的内在 当与伴侣形成特定的复合物时，蛋白质及其通路会发生紊乱。虽然后者是具体的， 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 在微观尺度上的分子识别的范例，介导的弱，非特异性相互作用之间的 分子系综。分子识别的第三个范例是蛋白质与蛋白质的半特异性结合。 膜，其中结合蛋白的构象和姿态以及近端脂质的组成 都是高度动态的。我们将深入探讨WASP和突触球蛋白与 酸性膜，以填补其功能机制中的关键空白。计划中的研究不仅 推进对生物学的基本理解，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.