STRUCTURES OF ALPHAVIRUS SPIKES AND RECEPTORS

甲病毒属是披膜病毒科的一个属。 因为他们的 广泛的组织特异性，这些包膜RNA病毒可以引起广泛的 各种严重的综合征;脑炎，心肌炎，肌痛， 肌腱炎关节炎和白细胞减少症 已经清楚地表明，在低pH值下，包膜糖蛋白 经历了巨大的构象变化，这些构象变化 代表膜融合过程的早期事件。 此外，本发明还提供了一种方法， 突变分析表明，刺突中少数残基的变化 蛋白质可以改变膜穿透率和神经毒性。 已经在许多这些刺突蛋白上确定了抗原表位， 并且已经发现一些与细胞受体结合区重叠。 这些研究和其他研究清楚地界定了 刺突蛋白，但需要结构信息，以更好地了解 甲病毒感染和抗体介导的机制 中和 我们计划检查几种甲病毒（辛德比斯，塞姆利基森林， 和罗斯河）和他们的各种改变状态使用的组合X- 射线晶体学和电子显微镜。 我们将使用晶体学 为了确定刺突蛋白的结构， 这些刺突蛋白和细胞受体。 由于大量的 重要的位点已经用诱变实验作图， 这些结构将产生大量关于 神经毒力、膜融合和抗体介导的过程 中和 这些结构也将用于以下方面： 电子显微镜图像来解释低分辨率结构， 不能使用晶体学方法检查的较大物种， 如病毒/受体复合物、病毒/抗体复合物和膜融合 前体

The Alphavirus is one genera of the Togaviridae family. Because of their broad tissue specificity, these enveloped RNA viruses can cause a wide variety of serious syndromes; encephalitis, myocarditis, myalgias, tendonitis, arthritis, and leukopenia. It has been clearly shown that at low pH the envelope glycoprotein spikes undergo large conformational changes, and these conformational changes represent early events in the membrane fusion process. In addition, mutational analysis has shown that changes in a few residues in the spike proteins can alter membrane penetration rates and neurovirulence. Antigenic epitopes have been determined on many of these spike proteins, and some have been found to overlap the cell receptor binding region. These and other studies have clearly defined important aspects of the spike proteins but structural information is needed to better understand the mechanisms of alphavirus infection and antibody mediated neutralization. We plan to examine several of the alphaviruses (Sindbis, Semliki Forest, and Ross River) and their various altered states using a combination of X- ray crystallography and electron microscopy. We will use crystallography to determine the structures of the spike proteins, immune complexes of these spike proteins, and the cellular receptors. Since a great number of important sites have already been mapped using mutagenesis experiments, these structures will yield a great deal of information as to the processes of neurovirulence, membrane fusion, and antibody mediated neutralization. These structures will also be used in the context of electron microscopy images to interpret the low resolution structures of larger species which cannot be examined using crystallographic means such as virus/receptor complexes, virus/antibody complexes, and membrane fusion precursors.