Protein Functional Dynamics and Energy Landscapes

我们感兴趣的是生物大分子，如蛋白质，功能。具体而言，我们提出了以下研究方向：1）蛋白质折叠。一旦在细胞中合成，蛋白质在百万分之一秒内自发地采用特定的3D形状（即折叠）。而且，他们通常不会出错。我们提出了一种折叠机制，其中蛋白质采用中间体，该中间体是膨胀的，但没有水。这些中间体对与蛋白质错误折叠相关的疾病（如阿尔茨海默氏症）有着深远的影响。2)淀粉样变性和蛋白质聚集。我们感兴趣的力量在发挥作用，引起蛋白质聚集，因为它适用于疾病。我们设计了一种方法来检测参与聚集的蛋白质的状态。3)酶功能动力学虽然我们对处于非活性和活性状态的酶有很多了解，但目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）的运动是如何协同作用使酶与底物结合并产生产物的？理解这些运动是理解函数的关键。利用核磁共振，我们可以捕捉细菌脱卤酶（一种同源二聚体脱氟酶，每个结构域由304个氨基酸组成）沿着反应途径的构象，并观察自发运动如何帮助酶发挥功能。这些结果使我们对酶的作用机制、构象预选、诱导匹配以及G蛋白偶联受体（GPCR）动力学的理解有了很大的进展。所有药物中有一半针对这些负责细胞信号传导的复杂膜蛋白。我们提议研究药物在众所周知的GPCR复杂能源格局中的作用。特定的药物是如何导致GPCR采用最终加速或减缓信号传导的状态的？这项工作有可能改变我们对GPCR激活和药效团影响的理解。

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.