Crystallographic studies of intact and fully glycosylated HIV-1 gp120

描述（由申请方提供）：HIV-1感染始于病毒和靶细胞膜的融合。病毒附着和膜融合由病毒包膜刺突在与宿主细胞受体接合时介导。成熟的包膜刺突包含三个拷贝的非共价相关受体结合亚基gp 120和融合亚基gp 41。尽管在过去的15年里，我们对HIV-1包膜糖蛋白结构的理解取得了相当大的进展，但由于与这种蛋白质的晶体学研究相关的巨大技术挑战，我们仍然没有全长和完全糖基化的gp 120的原子图像，这种蛋白质被大量的碳水化合物包裹。然而，这样的结构对于全面理解gp 120功能以及其与各种配体，特别是广泛中和抗体（bNAb）的相互作用至关重要。确定完整HIV-1 gp 120的原子结构将标志着HIV-1进入结构生物学的重要里程碑，也可能指导抗病毒治疗和疫苗的开发。我们已经获得了全长和完全糖基化的HIV-1 gp 120的衍射晶体。在本申请中，我们建议确定与几种中和抗体复合的完整和糖基化的HIV-1 gp 120的晶体结构。我们假设，未改变的HIV-1 gp 120的高溶液晶体结构将为gp 120功能，抗体中和和免疫逃避提供新的机制见解。我们将追求以下具体目标：1）我们将确定完整的、完全糖基化的HIV-1 gp 120的晶体结构; 2）我们将确定完整的gp 120与2结构域CD 4和抗CD 4抗体ibalizumab复合物的晶体结构; 3）我们将确定具有不同特征的HIV-1 gp 120的晶体结构。

DESCRIPTION (provided by applicant): HIV-1 infection begins with fusion of viral and target cell membranes. Viral attachment and membrane fusion are mediated by viral envelope spikes upon engagement with host cellular receptors. The mature envelope spikes contain three copies each of noncovalently-associated receptor-binding subunit gp120 and fusion subunit gp41. Despite considerable progress in our understanding of the structure of HIV-1 envelope glycoprotein over the last 15 years, we still do not have an atomic picture of the full-length and fully glycosylated gp120 due to enormous technical challenges associated with crystallographic studies of this protein, which is heavily coated with carbohydrates. Such a structure is, however, critical for a full understanding of gp120 function, as well as its interactions with various ligans, in particular, broadly neutralizing antibodies (bNAbs). Determination of an atomic structure of an intact HIV-1 gp120 will mark an important milestone in structural biology of HIV-1 entry, and may also guide development of antiviral therapeutics and vaccines. We have obtained diffracting crystals of a full-length and fully glycosylated HIV-1 gp120. In this application, we propose to determine crystal structures of the intact and glycosylated HIV-1 gp120 in complex with several neutralizing antibodies. We hypothesize that high-solution crystal structures of the unaltered HIV-1 gp120 will provide novel mechanistic insights into gp120 function, antibody neutralization and immune evasion. We will pursue the following specific aims: 1) We will determine the crystal structure of an intact, fully-glycosylated HIV-1 gp120; 2) We will determine the crystal structure of intact gp120 in complex with 2 domain CD4 and an anti-CD4 antibody ibalizumab; 3) We will determine crystal structures of HIV-1 gp120s with distinct characteristics.