Collaborative Research: Designing biomaterials through computational simulation and manipulation of phase behavior in a class of intrinsically disordered proteins

非技术概述缺乏确定结构的蛋白质在生物学和材料中起着许多重要作用，从细胞内部分子的组织到弹性材料的产生，这些弹性材料可以拉伸数倍于其原始长度而不会永久变形。尽管这些类型的蛋白质具有广泛的用途，但对定义其性质的分子特征的详细了解仍然刚刚出现，这限制了它们在高性能生物材料中的应用。该提案通过开发计算和实验方法来解决这一差距，这些方法将描述蛋白质的组成及其溶液的性质如何提供用于制造图案化弹性体基质的手柄，从长远来看，这将解决关键的社会挑战，例如工程活材料，控制生物分子的放置以进行化学功能，和/或更有效的能量存储。该计划的研究也将影响各种年龄和经验的学生的教育活动。一系列学生发起的活动和播客，其中PI将参与，将有助于将该计划的概念转移到中学课程和实践经验。技术概述两种不同溶液的液-液相分离（LLPS）是一个基本的热力学过程，在先进材料的开发和无膜细胞器（如核仁）的组装中具有重要意义。使用蛋白质LLPS有目的地设计新材料可以显着推进，如果更精细的细节是已知的选择功能的多肽链及其解决方案如何驱动的热力学和动力学的相分离的IDP。因此，该提案的总体目标是利用研究人员在节枝弹性蛋白样IDP（RLP）的计算机建模和重组设计中的独特能力，以设计在中尺度显示可调材料特性的蛋白质凝聚体。该项目将利用闭环形式，将最先进的蛋白质LLPS模拟与RLP的广泛实验表征相结合，以提供有关氨基酸组成，序列和共溶质（盐或PEG）在LLPS中作用的迭代反馈。实验确定的第二维里系数的变化，为选定的RLP，和他们的匹配（或偏差）从计算将使微调的计算方法。详细的光谱和散射表征将使相关的计算预测，并进一步用于建立凝聚层的浓度和水凝胶的形态和性质的组成的作用。总之，这些研究将加深对热力学和动力学的LLPS的IDPs的基本理解，并将允许前所未有的控制与控制的微观结构和组成的冷凝物的设计作为元素在biomaterials design.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Nontechnical SummaryProteins that lack defined structures play many important roles in biology and in materials, mediating functions from the organization of molecules in the interior of cells to the production of elastomeric materials that can stretch multiple times their original length without permanent deformation. Despite the widespread utility of these types of proteins, detailed understanding of the molecular features that define their properties is still just emerging, which has limited their application in high-performance biomaterials. This proposal addresses this gap by developing computational and experimental methods that will describe how the composition of the proteins and the properties of their solutions can provide handles for making patterned elastomeric matrices, which in the long term will address critical societal challenges such as engineering living materials, controlling placement of biomolecules to conduct chemical functions, and/or more efficient energy storage. The research in this program will also impact educational activities for students of a variety of ages and experience. A series of student-initiated activities and podcasts, in which the PIs will participate, will help transfer concepts of this program into secondary school curricula and hands-on experiences.Technical summaryLiquid-liquid phase separation (LLPS) of two dissimilar solutions is a fundamental thermodynamic process with significant importance in the development of advanced materials and for the assembly of membraneless organelles such as the nucleolus. The use of protein LLPS to purposefully design new materials could be significantly advanced if finer details were known about how select features of the polypeptide chain and its solutions drive the thermodynamics and kinetics of phase separation in the IDPs. The overarching goal of this proposal, accordingly, is to leverage unique capabilities of the investigators in computer modeling and recombinant design of resilin-like IDPs (RLPs) to design protein coacervates that display tunable material properties at the mesoscale. The project will leverage a closed-loop format, combining state-of-the-art simulations of protein LLPS alongside extensive experimental characterization of RLPs to provide iterative feedback about the role of amino acid composition, sequence, and co-solutes (salt or PEG) in LLPS. Variations in the experimentally determined second virial coefficients for selected RLPs, and their match (or deviation) from computation will enable fine-tuning of computational methods. Detailed spectroscopy and scattering characterization will enable correlation with computational prediction and further serve to establish the roles of coacervate concentration and composition in hydrogel morphology and properties. Taken together, these studies will deepen fundamental understanding of thermodynamics and kinetics of the LLPS of IDPs and will allow for unprecedented control over the design of condensates with controlled microstructure and composition as elements in biomaterials design.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.