Early Events in Protein Folding

项目摘要/摘要 结构-功能范式是一个强大的指导原则，它是我们许多理解的基础 关于生物过程的。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到其天然活性结构所必需的。此外，蛋白质的功能 需要这种天然结构随着时间的推移而演变。因此，蛋白质结构的动力学和 伴随的溶剂水提供了结构和功能之间的关键联系。的总目标是 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，这是一个对公共卫生有重大影响的问题。中探讨的机制 这项工作也适用于其他包膜病毒，特别是艾滋病毒。更广泛地说，膜融合 和通过蛋白质的质子传输是高度基本的兴趣，我们期望在 这些具体研究将有助于理解广泛的相关制度。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。我们将测试一种新型号的 基于分子动力学模拟的蛋白质介导膜融合。我们有 开发了基于激光诱导的pH跳跃来启动融合过程的独特方法，以及结构 表征驱动膜的血凝素复性动力学的特殊光谱方法 核聚变。该病毒蛋白可作为了解膜的一般机制的原型。 聚变作为一种无处不在的膜转运过程。 2)确定了熔融孔隙的形成机制。我们将检验血凝素的假设 跨膜结构域(TMD)和融合肽(FP)形成一个开放和稳定的寡聚复合体 融合孔。 3)确定主动门控质子输运的分子机制。这项工作将集中在 流感M2质子通道是一种重要的模式离子通道。理解质子的输运过程 蛋白质通道对许多基本的生物学过程以及流感病毒的复制都是至关重要的。 这些目标通过能源景观概念在智力上联系在一起，在操作上通过方法学联系在一起。 我们实验室为研究蛋白质和膜动力学而开发的。我们独特的方法将使我们能够 确定参与蛋白质介导膜融合和质子通道激活的特定蛋白质运动。 我们期待这项工作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.