Structures of HIV and SIV envelope glycoproteins

HIV 和 SIV 包膜糖蛋白的结构

• 批准号: 7087815
• 负责人: STEPHEN COPLAN HARRISON
• 金额: $ 16.5万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7087815
• 关键词: CD4 molecule; HIV envelope protein gp120; X ray crystallography; chemical addition; chemical structure function; conformation; cryoelectron microscopy; glycoprotein structure; human immunodeficiency virus; peptide chemical synthesis; protein structure function; receptor binding; receptor expression; simian immunodeficiency virus; virus infection mechanism; virus protein

DESCRIPTION (provided by applicant): The surface glycoproteins of enveloped viruses such as human and simian immunodeficiency viruses (HIV and SIV) mediate cell attachment and membrane fusion, thus allowing the virus to enter a new host cell. This proposal grows directly out of our recent determination, by x-ray crystallography at 3.9 A resolution, of the structure of unliganded (i.e., not bound to CD4 or to an Fab) and fully glycosylated SIV gp!20 core, the receptor-binding portion of the SIV envelope protein. Previous structural analyses of HIV-1 gp!20 core and of HIV-1 gp41 (the fusion-promoting fragment of the envelope protein) have yielded models for the postfusion conformations of these proteins, but the new structure now allows us to assess directly the conformational changes induced by receptor (CD4) and co-receptor (CXCR4 or CCR5) binding. We propose to use insights from the new structure to pursue 3 specific aims. First, we will generate stabilized forms of unliganded SIV gp120, by introduction of one or more additional disulfide bonds, to produce betterordered crystals and to provide a template for parallel design of stabilized HIV-1 gp120. Second, we will introduce similar disulfide links into HIV-1 gp120 and make other modifications, in order to crystallize it as an unliganded species. If successful, we will determine the structure in complex with 2 inhibitors that block an early step in viral entry: the small molecule, BMS-378806, and the peptide, 12pl. Third, we will design and produce stable, rigidified, and potentially crystallizable forms of the HIV and HIV gp140 trimer, the ectodomain of the form found on the virion surface. We will attempt to crystallize these trimers for x-ray structure determination, as well as to study them by single-particle cryo-EM. Our long-range goal is a complete "molecular movie" of the conformational changes in HIV/SIV envelope protein that allow it to mediate viral entry. By achieving this goal, we anticipate being able to generate concepts for novel antiretro viral therapeutics and for novel immunogens.

描述（由申请人提供）：诸如人和邻肌免疫缺陷病毒（HIV和SIV）的包膜病毒的表面糖蛋白介导细胞的附着和膜融合，从而使该病毒进入新的宿主细胞。该建议直接从我们最近的确定中，通过X射线晶体学以3.9分辨率，分辨率为无配置的结构（即与CD4或FAB不结合）和完全糖基化的SIV GP！20核心，SIV蛋白的受体结合部分。 HIV-1 GP！20核心和HIV-1 GP41（包膜蛋白融合促进片段）的先前结构分析为这些蛋白质的凹入后构象产生了模型，但是新结构现在允许我们直接评估受体（CD4）和coxcr4或CCR4或CCR5诱导的构象变化。我们建议利用新结构中的见解来追求3个特定目标。首先，我们将通过引入一个或多个额外的二硫键键来生成稳定的SIV GP120的形式，以产生排序较好的晶体，并为稳定的HIV-1 GP120的平行设计提供模板。其次，我们将在HIV-1 GP120中引入类似的二硫键并进行其他修饰，以将其结晶为无物种。如果成功，我们将确定与2个抑制剂的复合物中的结构，这些抑制剂阻止了病毒入口的早期步骤：小分子BMS-378806和肽，12PL。第三，我们将设计并产生稳定，僵化且可能结晶的HIV和HIV GP140夹子，这是在病毒体表面上发现的形式的e骨架。我们将尝试将这些三聚体结晶以确定X射线结构，并通过单粒子冷冻EM进行研究。我们的远程目标是一部完整的“分子电影”，用于艾滋病毒/SIV包膜蛋白的构象变化，使其能够介导病毒进入。通过实现这一目标，我们预计能够为新颖的抗逆转录病毒疗法和新型免疫原子产生概念。