CONFORMATIONAL CHANGES OF VIRAL PROTEINS DURING INFECTION AND ASSEMBLY

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们建议使用溶液、小角X射线散射来研究两种病毒蛋白：流感血凝素和乙肝病毒衣壳蛋白的结构和构象动力学。这些研究将侧重于产生中等分辨率的3D重建以及对时间分辨的结构变化进行量化分析。被包裹的病毒，如流感病毒，使用专门的蛋白质机制将它们的膜与宿主细胞的细胞膜融合，并传递它们的基因组以供复制。在流感病毒中，三聚体血凝素(HA)糖蛋白负责宿主细胞的附着和膜融合。从机械上理解生物机器，如HA，既需要详细的结构，也需要了解支配它们功能的动力学和能量学。积极推动融合过程的状态已被证明是难以确定经典结构的。SAXS将被用来弥合我们对HA结构理解上的重大差距，并利用时间分辨研究来表征HA介导膜融合的机制。我们对乙肝病毒衣壳的研究主要集中在组装和药物诱导的错误组装过程。乙肝病毒是少数几个病毒与针对其保护性衣壳的药物之间相互作用的系统之一，在结构和生化上都得到了很好的表征。因此，它是探索病毒结构和功能关系的理想系统。将开展乙肝病毒衣壳组装反应的时间分辨研究，以确定成核状态并监测乙肝病毒衣壳的组装反应。接下来，我们将研究抗病毒化合物对乙肝病毒衣壳组装的调节作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We propose to use solution, small-angle x-ray scattering to study the structure and conformational dynamics of two viral proteins: influenza hemagglutinin and the hepatitis B virus capsid protein. The studies will focus on generating moderateresolution 3D reconstructions as well as quantitative analysis of time-resolved structural changes. Enveloped viruses such as influenza virus use specialized protein machinery to fuse their membrane with the cellular membrane of host cells and deliver their genome for replication. In influenza virus, the trimeric hemagglutinin (HA) glycoprotein is responsible for both host cell attachment and membrane fusion. A mechanistic understanding of biological machines such as HA requires both detailed structures and an understanding of the dynamics and energetics that govern their function. The states that actively drive the fusion process have proven to be refractory to classical structure determination. SAXS will be used to bridge the significant gaps in our structural understanding of HA and to characterize the mechanism of HA-mediated membrane fusion using time-resolved studies. Our proposed studies of hepatitis B virus (HBV) capsids focus on the assembly and drug-induced misassembly processes. HBV is one of the few systems for which interactions between virus and drugs targeted against its protective capsid have been well characterized both structurally and biochemically. It is thus an ideal system for exploring the relation of virus structure and function. Time-resolved studies of HBV capsid assembly reactions will be carried out to identify nucleation states and to monitor the assembly reaction of HBV capsids. Next, the modulation of HBV capsid assembly by antiviral compounds will be investigated.