Bi-substrate Inhibitors of SARS-CoV-2 Nsp14 Methyltransferase

摘要 严重急性呼吸系统综合征冠状病毒2型（SARS-CoV-2），目前大流行的病原体 2019冠状病毒病（COVID-19）的爆发，已构成现代历史上前所未有的全球健康威胁。 虽然疫苗、抗体和抗病毒药物瑞德西韦的批准为结束这一局面带来了希望 毁灭性的大流行、最近出现的传染性更强的变异体和迅速传播要求我们重新努力 开发有效的治疗方法来对抗SARS-CoV-2感染。在SARS-CoV-2中，RNA 5′-帽结构是 甲基化以确保病毒翻译/复制并逃避宿主免疫监视。我们打算发现 鸟嘌呤N7-甲基转移酶（N7-MTase，Nsp 14）的选择性抑制剂，因为Nsp 14的活性位点 MTase是独特的收缩，而人类RNA加帽MTase是过度开放的。此外，收缩 Nsp 14 MTase活性位点的性质允许我们设计双底物抑制剂。我们的初步努力 导致显示出优异的抗SARS-CoV-2活性和无显著细胞毒性的纳摩尔抑制剂。在这 应用程序，我们将进行铅优化，以提高效力，选择性和药物样的性质，我们的 Nsp 14 MTase抑制剂，旨在鉴定MTase抑制剂，用于未来的动物概念验证研究 SARS-CoV-2感染模型。为了实现这一目标，我们提出了以下具体目标： 1. SARS-CoV-2 Nsp 14 MTase抑制剂的设计与合成及其生物化学和抗病毒活性评价 具体目标2.评估选定的SARS-CoV-2 Nsp 14 MTase抑制剂的理化和生物学特性， 体外吸收、分布、代谢、排泄和毒性（ADMET）特性;和特定目标3。 测定晚期SARS-CoV-2 Nsp 14 MTase抑制剂的体内药代动力学（PK）参数。我们 我希望这项研究将对开发SARS-CoV-2 Nsp 14 MTase做出重大贡献 抑制剂作为COVID-19治疗剂。

ABSTRACT Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of the current pandemic of coronavirus disease 2019 (COVID-19), has posed an unprecedented global health threat in modern history. While the approvals of vaccines, antibodies, and antiviral drug remdesivir have offered hope to end this devastating pandemic, recent emergence and rapid spread of more infectious variants calls for renewed efforts to develop effective therapies to combat SARS-CoV-2 infection. In SARS-CoV-2, the RNA 5′-cap structure is methylated to ensure viral translation/replication and to evade host immune surveillance. We propose to discover selective inhibitors of guanine N7-methyltransferase (N7-MTase, Nsp14) because the active site of Nsp14 MTase is uniquely constricted while human RNA capping MTases are overly open. Furthermore, the constricted nature of the Nsp14 MTase active site has allowed us to design bi-substrate inhibitors. Our preliminary effort has led to a nanomolar inhibitor that shows excellent anti-SARS-CoV-2 activity and no significant cytotoxicity. In this application, we will perform lead optimization to improve the potency, selectivity and drug-like properties of our Nsp14 MTase inhibitors, aiming to identify MTase inhibitors for use in future proof-of-concept studies in animal models of SARS-CoV-2 infection. To accomplish the goal, we propose the following specific aims: Specific Aim 1. Design and synthesize SARS-CoV-2 Nsp14 MTase inhibitors and evaluate them in biochemical and antiviral assays; Specific Aim 2. Assess selected SARS-CoV-2 Nsp14 MTase inhibitors for their physiochemical and in vitro absorption, distribution, metabolism, excretion and toxicity (ADMET) properties; and Specific Aim 3. Determine in vivo pharmacokinetics (PK) parameters of advanced SARS-CoV-2 Nsp14 MTase inhibitors. We expect that the proposed research will significantly contribute to efforts in developing SARS-CoV-2 Nsp14 MTase inhibitors as COVID-19 therapeutics.