Heteropolymeric Semi-Autonomous Repeat Proteins: Coupling Energetics, Structure, and Function

杂聚半自主重复蛋白：能量学、结构和功能的耦合

• 批准号: 1947561
• 负责人: Douglas Barrick
• 金额: $ 90万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1947561&HistoricalAwards=false
• 关键词: Heteropolymeric; Semi; Autonomous; Repeat; Proteins

Proteins are large molecules that play many critical roles in the body. In this research project, experiments will be performed to learn how protein molecules interact with each other. Proteins often stick together or bind to other proteins of the same type, or of different types, and these types of interactions are critical to protein structure, function, and stability. Though it is fairly easy to "see" these interactions by determining structures of protein complexes, the rules by which the different parts of proteins bind are not known. Here, a series of proteins have been identified in which the protein subunits that bind are all in a single protein chain, making studies of their interactions quite simple to study. Studies will take advantage of the architecture of these "tandem repeat proteins" to learn the rules by which protein subunits stick together. These rules will reveal not only why tandem repeats stick together, but also why separate protein chains stick together. Thus these rules will provide an understanding of protein structure and function in complexes ranging from pairs of protein chains all the way up to the very large protein assemblies that give cells and tissues their shapes and mechanical properties and allow cells to communicate with each other. This research will help train students, both at the undergraduate and graduate level, in the methods of cutting-edge biophysics and biochemistry, both in the laboratory and through the use of computer simulations.These studies will use experimental and computational methods. Fragments of five different proteins will be prepared in the lab, and their structures will be studied with x-ray diffraction and magnetic resonance spectroscopy. Fragment stabilities will be determined using optical techniques like fluorescence and circular dichroism spectroscopy. Computer simulations will also be used to learn what types of interactions promote interaction between protein subunits. A key aspect of this research project is that the repeating structure of proteins studied here can be analyzed with a model called an "Ising" model. This model allows the precise measurement of the strength of interaction between protein subunits. The rules that are learned from this analysis will apply not only to other repeat proteins, but to non-repeating protein assemblies, which use the same types of interactions (packing, charge interactions, and hydrogen bonding) as repeat proteins do.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.

蛋白质是大分子，在体内发挥着许多关键作用。 在这个研究项目中，将进行实验，以了解蛋白质分子如何相互作用。 蛋白质经常粘在一起或与相同类型或不同类型的其他蛋白质结合，这些类型的相互作用对蛋白质的结构，功能和稳定性至关重要。 虽然通过确定蛋白质复合物的结构很容易“看到”这些相互作用，但蛋白质不同部分结合的规则尚不清楚。 在这里，一系列的蛋白质已经被确定，其中结合的蛋白质亚基都在一个单一的蛋白质链中，使得研究它们的相互作用非常简单。 研究将利用这些“串联重复蛋白质”的结构来了解蛋白质亚基粘在一起的规则。 这些规则不仅将揭示为什么串联重复序列粘在一起，而且还将揭示为什么单独的蛋白质链粘在一起。 因此，这些规则将提供对蛋白质结构和功能的理解，从成对的蛋白质链一直到非常大的蛋白质组装体，这些蛋白质组装体赋予细胞和组织形状和机械特性，并允许细胞相互交流。这项研究将有助于培养学生，无论是在本科生和研究生水平，在尖端的生物物理学和生物化学的方法，无论是在实验室和通过使用计算机模拟。这些研究将使用实验和计算方法。 将在实验室中制备五种不同蛋白质的片段，并将用X射线衍射和磁共振光谱研究它们的结构。 将使用光学技术如荧光和圆二色谱法测定片段稳定性。 计算机模拟也将用于了解什么类型的相互作用促进蛋白质亚基之间的相互作用。 该研究项目的一个关键方面是，这里研究的蛋白质的重复结构可以用一种称为“伊辛”模型的模型进行分析。 该模型允许精确测量蛋白质亚基之间的相互作用强度。 从这项分析中学到的规则不仅适用于其他重复蛋白质，也适用于非重复蛋白质组装体，它们与重复蛋白质使用相同类型的相互作用（包装，电荷相互作用和氢键）。该奖项反映了NSF的法定使命，并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，被认为值得支持。