INSPIRE: Concentrated Dispersions of Equilibrium Protein Nanoclusters that Reversibly Dissociate into Active Monomers

INSPIRE：平衡蛋白纳米簇的浓缩分散体，可可逆地解离成活性单体

• 批准号: 1247945
• 负责人: Thomas Truskett
• 金额: $ 60万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1247945&HistoricalAwards=false
• 关键词: INSPIRE; Concentrated; Dispersions; Equilibrium; Protein

This INSPIRE award to University of Texas at Austin by the Interfacial Processes and Thermodynamics program in the Division of Chemical, Bioengineering, Environmental and Transport (CBET) in the Directorate for Engineering (ENG) is cofunded by the Particulate and Multiphase Processes in the CBET-ENG; and the Biomaterials program in the Division of Materials Research in the Directorate for the Mathematical and Physical Sciences. Protein-based drugs represent some of the most promising therapies for a wide range of diseases, including cancer. Subcutaneous injection is the preferred method of delivery, but its usefulness is currently limited by unwanted outcomes such as protein aggregation and gelation that occur for high doses. Previous attempts to address these problems by modifying the amino-acid sequence of potential therapeutics have been expensive and often unsuccessful. The investigators have recently reported a new method for creating highly concentrated, low-viscosity dispersions of stable protein nanoclusters that are not only of great fundamental interest but also could provide a basis for an unconventional means for solving major challenges in the protein-based therapeutics. However, at present, the answers to basic questions about the origins of the nanoclusters are lacking. Furthermore, the relationships between specific nanocluster characteristics and physical properties of the resulting dispersions are currently unknown.Intellectual MeritThe aqueous protein nanocluster dispersions to be studied in this proposal represent an entirely new form of soft condensed matter. The goal of the proposal is to explore and develop a fundamental understanding of how the protein nanoclusters form, why they stabilize the folded state of the proteins, and the impact of the clusters on the physical properties of dispersions. The investigators will use experiments, statistical mechanical theory, and computer simulations to test the hypothesis that clusters spontaneously form due to an equilibrium, self-assembly process where the addition of a small molecule ?crowder? molecule induces attractions between proteins that are balanced by weak electrostatic repulsions near the protein?s isoelectric point. In doing so, they will also address key open questions about the pathway dependence of nanocluster dispersions, the role and design of novel molecular crowders in nanocluster assembly, and the structure and dynamics of the nanoclusters. Since protein nanocluster dispersions are inherently multiscale (clusters, proteins, crowders, and solvent each introduce characteristic length scales), they are challenging to characterize experimentally. The PIs will determine the extent to which light-scattering, cryo-SEM and TEM, neutron scattering, and x-ray scattering can be used provide insights into the structure, dynamics, and stability of self-crowded proteins in the nanoclusters. They will also investigate appropriate multiscale strategies for modelingthese systems.Broader ImpactsIf successful, the proposed research will provide resolutions to important fundamental questions about the possibility of forming aqueous dispersions of equilibrium nanoclusters with tunable size that dissociate to monomers upon dilution. Anticipated outcomes include a general method for creating (and tuning the properties of) aqueous nanocluster dispersions of interest for technologies that range fromdrug delivery to biofuel production, as well as a theoretical understanding for why previous attempts using alternative strategies were only able to produce nanoclusters that were small, dilute, and short lived. In this grant, both undergraduate and graduate students will have the opportunity to work on important fundamental research with unusually strong interdisciplinary and technological components. In addition to other outreach efforts, the PIs propose to integrate the science on protein stability and crowding from the project into an undergraduate course on biological physics through a series of interactive, simulation- and theory-based modules.

该INSPIRE奖由工程理事会（ENG）化学，生物工程，环境和运输部（CBET）的界面过程和热力学计划授予德克萨斯大学奥斯汀分校，由CBET-ENG的颗粒和多相过程共同资助;以及数学和物理科学理事会材料研究部的生物材料计划。基于蛋白质的药物代表了包括癌症在内的各种疾病的一些最有前途的疗法。皮下注射是优选的递送方法，但其有效性目前受到不希望的结果的限制，例如高剂量时发生的蛋白质聚集和凝胶化。先前通过修饰潜在治疗剂的氨基酸序列来解决这些问题的尝试是昂贵的并且通常不成功。研究人员最近报道了一种新的方法，用于创建稳定的蛋白质纳米团簇的高浓度，低粘度分散体，这不仅具有很大的根本利益，而且可以为解决基于蛋白质的治疗中的主要挑战的非常规手段提供基础。然而，目前，关于纳米团簇的起源的基本问题的答案是缺乏的。此外，具体的纳米团簇的特性和物理性质之间的关系，所产生的dispersions.Intellectual MeritThe水性蛋白质纳米团簇分散体的研究，在这个建议代表了一个全新的形式的软凝聚物质。该提案的目标是探索和发展对蛋白质纳米簇如何形成的基本理解，为什么它们稳定蛋白质的折叠状态，以及簇对分散体物理性质的影响。研究人员将使用实验，统计力学理论和计算机模拟来测试集群自发形成的假设，由于一个平衡，自组装过程中，添加一个小分子？crowder？分子诱导蛋白质之间的吸引力，通过蛋白质附近的弱静电排斥来平衡？s等电点。在这样做的过程中，他们还将解决有关纳米团簇分散体的路径依赖性，纳米团簇组装中新型分子拥挤物的作用和设计，以及纳米团簇的结构和动力学的关键开放问题。由于蛋白质纳米团簇分散体本质上是多尺度的（团簇、蛋白质、拥挤物和溶剂各自引入特征长度尺度），因此它们在实验上具有挑战性。PI将确定光散射，cryo-SEM和TEM，中子散射和X射线散射可以用于提供对纳米团簇中自拥挤蛋白质的结构，动力学和稳定性的见解的程度。他们还将研究适当的多尺度策略modelingthese systems.Broader impactsIf成功的，拟议的研究将提供解决方案的重要的基本问题的可能性形成的水分散体的平衡纳米团簇与可调的大小，解离单体稀释后。预期的成果包括一个一般的方法，用于创建（和调整的属性）感兴趣的技术，从药物输送到生物燃料生产的纳米团簇水分散体，以及理论上的理解，为什么以前的尝试使用替代策略只能产生纳米团簇是小的，稀释的，和短暂的。在这个补助金，本科生和研究生都将有机会从事重要的基础研究与异常强大的跨学科和技术组成部分。除了其他外展工作外，PI还建议通过一系列交互式，模拟和理论为基础的模块，将该项目中关于蛋白质稳定性和拥挤的科学纳入生物物理学本科课程。