Early Events in Protein Folding

项目总结/摘要 结构-功能范式是一个强有力的指导原则，是我们理解的基础 的生物过程。然而，在这幅图中经常被忽视的是蛋白质结构的灵活性。 这种灵活性是蛋白质折叠成其天然活性结构所必需的。此外，蛋白质功能 需要这种天然结构随着时间的推移而进化。因此，蛋白质结构的动力学和 相关的溶剂水提供了结构和功能之间的关键联系。的总目标 本研究旨在阐明血凝素和M2质子通道的功能动力学， 流感病毒感染是一个对公共卫生有重大影响的问题。研究的机制 这项工作也与其他包膜病毒，特别是HIV有关。更一般地说，膜融合 和质子通过蛋白质的运输是高度的根本利益，我们希望获得的见解， 这些具体的研究将有助于了解广泛的相关系统。我们计划 追求三个具体目标： 1)确定血凝素介导膜融合的机制。我们将测试一种新的模式， 蛋白质介导的膜融合是基于分子动力学模拟这一过程。我们有 开发了基于激光诱导pH值跳跃的独特方法来启动融合过程， 特定的光谱方法来表征驱动膜的血凝素重折叠动力学 核聚变这种病毒蛋白质作为理解膜的一般机制的原型， 融合作为一种普遍存在的膜转运过程。 2)确定了熔合孔的形成机理。我们将检验血凝素 跨膜结构域（TMD）和融合肽（FP）形成寡聚复合物， 融合孔 3)确定主动门控质子转运的分子机制。这项工作将集中在 流感病毒M2质子通道，一个重要的模型离子通道。了解质子通过 蛋白质通道对于许多基本的生物过程以及流感病毒的复制是至关重要的。 这些目标在智力上通过能源景观概念联系起来，在操作上通过方法联系起来 在我们的实验室开发的用于研究蛋白质和膜动力学。我们独特的方法将使我们能够 鉴定参与蛋白质介导的膜融合和质子通道激活的特定蛋白质运动。 我们希望这项工作能够为塑造能源格局的因素提供重要的新见解。 膜蛋白和耦合的膜动力学。

Project Summary/Abstract The structure-function paradigm is a powerful guiding principle that underlies much of our understanding of biological processes. What is often neglected in this picture, however, is the flexibility of protein structures. This flexibility is necessary for a protein to fold to its native, active structure. Furthermore, protein function requires evolution of this native structure with time. Therefore, the dynamics of the protein structure and associated solvent water provide the critical connection between structure and function. The overall goal of this proposal is to elucidate the functional dynamics of hemagglutinin and M2 proton channel that enable influenza virus infection, a problem with significant public health implications. The mechanisms explored in this work are also relevant to other enveloped viruses, in particular HIV. More generally, membrane fusion and proton transport through proteins are of high fundamental interest and we expect the insight gained in these specific studies will contribute to the understanding of a broad range of related systems. We plan to pursue three specific aims: 1) Determine the mechanism of hemagglutinin mediated membrane fusion. We will test a new model for protein mediated membrane fusion that is based on molecular dynamics simulations of this process. We have developed unique methodology base on a laser induced pH jump to initiate the fusion process, and structure specific spectroscopic methods to characterize the hemagglutinin refolding dynamics that drive membrane fusion. This viral protein serves as an archetype for understanding the general mechanism of membrane fusion as a ubiquitous membrane transport process. 2) Determine the mechanism of fusion pore formation. We will test the hypothesis that the hemagglutinin trans-membrane domain (TMD) and fusion peptide (FP) form an oligomeric complex that opens and stabilizes the fusion pore. 3) Determine the molecular mechanism of actively gated proton transport. This work will on a focus on the influenza M2 proton channel, an important model ion channel. Understanding transport of protons through protein channels is critical to many essential biological processes as well as replication of the influenza virus. These aims are linked intellectually by energy landscape concepts and operationally by the methodology developed in our lab for studying both protein and membrane dynamics. Our unique approach will allow us to identify specific protein motions involved in protein mediated membrane fusion and proton channel activation. We expect this work to provide important new insight into the factors that shape the energy landscape of membrane proteins and the coupled membrane dynamics.