冠状病毒RNA加帽酶抑制剂的筛选及抑制机制研究

RNA viruses which replicate and transcribe in cytoplasm, such as coronaviruses, infect human, bird, livestock, and closely contact with human society, cause a great threat and economic loss. We found that nonstructural protein nsp14 and nsp16 / Nsp10 complex of SARS coronavirus (SARS-CoV) possess N7- and 2'- O- methyl transferase activity, which involved in viral RNA 5' end capping process. These viral RNA capping enzymes are important to viral RNA stability, viral protein translation, viral immune escape and many other aspects. This study will focuse on the coronaviridae virus RNA capping mechanisms and capping enzymes as potential drug targets. Based on our previous work, we are planning to screen small molecular compounds which inhibit the activities of coronavirus RNA capping enzymes, through bioinformatics prediction and yeast genetic screenning system in vivo. And biochemical assays in vitro will be use to illuminate the mechanisms of these inhibitors, further revealing viral RNA cap mechanism. Finally, cell and animal models will be use to validate the inhibition efficiency. These studies will promote the development of antiviral drugs, which could also be used for inhibit other cytoplasmic replication viruses.

以SARS冠状病毒和人冠状病毒为代表的，细胞质内复制的冠状病毒主要感染人、禽、畜，与人类社会密切接触，造成巨大威胁和经济损失。我们研究发现SARS冠状病毒非结构蛋白nsp14和nsp16/nsp10复合体分别具有N7－和2'-O-甲基转移酶活性，参与病毒RNA的5'端加帽过程，是病毒RNA帽子合成的必须蛋白之一，影响病毒RNA的稳定，病毒蛋白翻译，参与病毒免疫逃逸等方面。本研究将探索冠状病毒科中病毒RNA加帽机制的普遍规律，作为潜在的药物靶点，用我们前期工作建立的研究基础，通过生物信息学预测，设计并大量筛选抑制冠状病毒RNA加帽酶功能的各种小分子化合物。结合体外生化活性实验，深入研究抑制剂的工作机理，揭示加帽机制，并在细胞及动物模型上验证其抑制效率。这些研究将有利于我们高开发特异抗病毒药物，且具有较高的推广及应用潜力，也可用于其他细胞质内复制的RNA病毒的药物开发，对病毒病的防治提供储备。

冠状病毒RNA的加帽机制目前仍不清楚，且缺乏有效的病毒防治手段。本项目系统解析了冠状病毒RNA加帽的作用机制及其RNA相关加帽酶的结构功能关系，证明了冠状病毒nsp14和nsp10/nsp16具有高度的保守性。并基于其特点，设计了特异性的抑制剂，能够在动物水平有效抑制病毒的复制。同时也揭示了宿主抗病毒天然免疫调控的新机制。这些成果一共发表SCI论文7篇，其中二区TOP 4篇（标注支助），申请专利二项，目前还有至少2篇SCI论文正在撰写和投稿中。这些研究将有利于我们高开发特异抗病毒药物，且具有较高的推广及应用潜力，也可用于其他细胞质内复制的RNA 病毒的药物开发，对病毒病的防治提供储备。