Structural Studies of Coronavirus Fusion Proteins

被包裹的病毒使用存在于病毒表面的特殊蛋白质来转移其基因 在感染过程中穿过宿主细胞膜的物质。对于冠状病毒，尖峰的同源三聚体 糖蛋白促进宿主细胞的附着和病毒与宿主膜的融合。虽然 冠状病毒有很大的流行潜力，缺乏高分辨率的数据 冠状病毒尖峰三聚体限制了我们对这类病毒感染的机械理解。 拟议工作的目标是获得对应于 冠状病毒尖峰蛋白介导的融合反应的不同阶段及其结构研究 与抗体抑制病毒感染相关的决定因素。在Aim I中，我们建议澄清 利用低温电子显微镜研究小鼠肝炎病毒(MHV)融合前尖峰的结构。AIM II将是 致力于研究与聚合体反应相关的构象变化 重点放在第一个中间阶段(延伸的中间阶段)和融合后的峰值。在AIM III中，我们 将描述人类冠状病毒尖峰的3D组织，以了解这些病毒如何 克服物种障碍并确定潜在的结构保守区域 治疗举措的目标。最终目标将依赖于结构指导的蛋白质设计来进行工程设计 针对人类冠状病毒的抗体尖峰，目的是识别免疫原以提高 广谱中和抗体。

Enveloped viruses use specialized proteins present at the virus surface to translocate their genetic material across the host cell membrane during infection. For coronaviruses, homotrimers of the spike glycoprotein promote host cell attachment and fusion of the viral and host membranes. Although coronaviruses have a significant pandemic potential, the lack of high-resolution data for any coronavirus spike trimer limits our mechanistic understanding of infection by this family of viruses. The objective of the proposed work is to obtain high-resolution snapshots corresponding to the various stages of the fusion reaction mediated by coronavirus spikes and to study the structural determinants associated with antibody inhibition of viral infection. In Aim I, we propose to elucidate the architecture of the Mouse Hepatitis Virus (MHV) pre-fusion spike using cryoEM. Aim II will be dedicated to studying the conformational changes associated with the fusion reaction with an emphasis on the first intermediate (extended intermediate) and the post-fusion spike. In Aim III, we will characterize the 3D organization of human coronavirus spikes to understand how these viruses overcome the species barrier and to identify structurally conserved regions that could be potential targets for therapeutic initiatives. The final aim will rely on structure-guided protein design to engineer antibodies targeting human coronavirus spikes with the goal of identifying immunogens for raising broadly-neutralizing antibodies.