Protein Functional Dynamics and Energy Landscapes

蛋白质功能动力学和能量景观

• 批准号: 261980-2013
• 负责人: Prosser, RobertScott
• 金额: $ 7.21万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632535
• 关键词: Protein; Functional; Dynamics; Energy; Landscapes

We are interested in how biological macromolecules, such as proteins, function. Specifically, we propose the following lines of study: 1) Protein Folding. Once synthesized in a cell, proteins, spontaneously adopt a specific 3D shape (i.e. fold) in millionths of a second. Moreover, they accomplish this usually without error. We propose a folding mechanism in which the protein adopts an intermediate which is expanded, yet devoid of water. There are profound consequences of such intermediates to diseases associated with protein misfolding, such as Alzheimer's. 2) Amyloidosis and Protein Aggregation. We are interested in the forces at play which give rise to protein aggregation, as it applies to disease. We have devised a way to detect states of proteins involved in aggregation. 3) Enzyme Functional Dynamics. While much is known about enzymes in their inactive and active states, the current challenge is to piece together how enzymes speed up chemical reactions. How do very fast (picoseconds) and very slow (micro and millisecond) motions conspire to allow the enzyme to engage its substrate and churn out product? Understanding these motions is key to understanding function. Using NMR we can capture conformations of a bacterial dehalogenase enzyme (a homodimeric defluorinase, consisting of 304 amino acids per domain) along the reaction pathway and see how spontaneous motions aid the enzyme in its function. The results allow us to greatly advance our understanding of enzyme mechanism, conformational preselection, and induced fit, and 4) G protein coupled receptor (GPCR) dynamics. Half of all drugs target these complex membrane proteins responsible for cell signaling. We are proposing to study the role of drugs on the complex energy landscape of a well-known GPCR. How do specific drugs cause the GPCR to adopt states that ultimately speed up or slow down signalling? The proposed work has the potential to transform our understanding of GPCR activation, and the influence of pharmacophores.

我们对生物大分子（例如蛋白质）如何发挥作用感兴趣。具体来说，我们提出以下研究方向：1）蛋白质折叠。一旦在细胞中合成，蛋白质就会在百万分之一秒内自发地形成特定的 3D 形状（即折叠）。而且，他们通常可以毫无错误地完成此任务。我们提出了一种折叠机制，其中蛋白质采用膨胀但不含水的中间体。这些中间体对与蛋白质错误折叠相关的疾病（例如阿尔茨海默病）具有深远的影响。 2）淀粉样变性和蛋白质聚集。我们对引起蛋白质聚集的作用力感兴趣，因为它适用于疾病。我们设计了一种检测参与聚集的蛋白质状态的方法。 3）酶功能动力学。虽然人们对酶的非活性和活性状态了解很多，但当前的挑战是拼凑酶如何加速化学反应。非常快（皮秒）和非常慢（微秒和毫秒）的运动如何共同让酶与其底物结合并产生产物？理解这些运动是理解功能的关键。使用 NMR，我们可以捕获细菌脱卤酶（同型二聚体脱氟酶，每个结构域由 304 个氨基酸组成）沿反应途径的构象，并了解自发运动如何帮助酶发挥其功能。这些结果使我们能够极大地增进对酶机制、构象预选和诱导拟合以及 4) G 蛋白偶联受体 (GPCR) 动力学的理解。一半的药物都针对这些负责细胞信号传导的复杂膜蛋白。我们提议研究药物对著名 GPCR 复杂能量景观的作用。特定药物如何导致 GPCR 采取最终加速或减慢信号传导的状态？这项工作有可能改变我们对 GPCR 激活和药效团影响的理解。