CONFORMATIONAL CHANGES OF VIRAL PROTEINS DURING INFECTION AND ASSEMBLY

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们建议使用解决方案，小角X-射线散射来研究两种病毒蛋白质的结构和构象动力学：流感血凝素和B型肝炎病毒衣壳蛋白。这些研究将侧重于生成中等分辨率的3D重建以及时间分辨结构变化的定量分析。包膜病毒如流感病毒使用专门的蛋白质机制将其膜与宿主细胞的细胞膜融合，并递送其基因组进行复制。在流感病毒中，三聚体血凝素（HA）糖蛋白负责宿主细胞附着和膜融合。对HA等生物机器的机械理解需要详细的结构以及对支配其功能的动力学和能量学的理解。主动驱动聚变过程的状态已被证明是经典结构测定难治的。SAXS将用于弥合我们对HA结构理解的重大差距，并使用时间分辨研究表征HA介导的膜融合机制。我们对B型肝炎病毒（HBV）衣壳的研究主要集中在组装和药物诱导的错误组装过程。HBV是为数不多的系统之一，针对其保护性衣壳的病毒和药物之间的相互作用已经在结构和生物化学上得到了很好的表征。因此，它是研究病毒结构与功能关系的理想系统。将进行HBV衣壳组装反应的时间分辨研究，以鉴定成核状态并监测HBV衣壳的组装反应。接下来，将研究抗病毒化合物对HBV衣壳组装的调节。

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.