Design & Synthesis of SARS Protease Inhibitors

该项目的主要目标是利用我们广泛的初步结果来设计和开发 SCLpro 抑制剂，用于严重急性呼吸综合征 (SARS) 的治疗干预。自2002年11月在中国广东省首次报告以来，SARS已蔓延到其他亚洲国家、北美和欧洲。截至 2003 年 7 月，这种流行病已经影响了 8000 多人，并导致 774 人死亡。最近发现的一种冠状病毒已被确定为 SARS 的病原体。到目前为止，还没有针对这种病毒的有效疗法。在病毒复制过程中，功能性多肽 由多蛋白通过 33.1-kD HCoV 229E 主要蛋白酶（称为 3C 样蛋白酶 (SCLpro)）进行蛋白水解加工而产生，这种 SCLpro 蛋白酶的活性对于冠状病毒复制至关重要。因此，这种蛋白酶被认为是针对 SARS 及相关感染的药物开发的有吸引力的靶标。前期工作中，我们根据SCLpro的X射线晶体结构、猪传染性胃肠炎（冠状）病毒（TGEV Mpro）相关酶的X射线晶体结构以及底物类似物六肽基氯甲基酮（CMK），设计并合成了多种SCLpro蛋白酶抑制剂 抑制剂，以及源自 SCLpro 活性位点的模型化抑制剂 AG-7088 的结构信息。其中两种抑制剂不仅对 SARS-SCLpro 具有相当的活性，而且在 50 至 100 微摩尔浓度下也能抑制 MHV（小鼠肝炎病毒）和 SARS-HCoV 细胞培养测定。我们还以 1.9 埃的分辨率确定了这些抑制剂与 SARS-SCLpro 复合物的 X 射线结构。这项工作现在构成了我们拟议研究的基础，其中合成药物化学的力量将与晶体学和分子建模相结合，并用于进一步开发具有临床潜力的新一代结构多样且更有效的抑制剂。

The main objective of this project is to utilize our extensive preliminary results to design and develop SCLpro inhibitors for therapeutic intervention of Severe Acute Respiratory Syndrome (SARS). Since its first report in Guangdong Province, China, in November, 2002, SARS has spread to other Asian countries, North America and Europe. This epidemic already affected more than 8000 reported individuals by July, 2003, and resulted in 774 deaths. A recently discovered coronavirus has been identified as the etiological agent for SARS. Thus far, no effective therapy exists for this virus. During viral replication, the functional polypeptides are generated from polyproteins by proteolytic processing carried out by a 33.1-kD HCoV 229E main protease that is called 3C-like protease (SCLpro) and the activity of this SCLpro protease is critical to coronavirus replication. Thus, this protease is recognized as an attractive target for drug development for SARS and related infections. In preliminary work, we designed and synthesized a number of SCLpro protease inhibitors based upon the X-ray crystal structure of SCLpro, the X-ray crystal structure of related enzyme of porcine transmissible gastroenteritis (corona)virus (TGEV Mpro) with a substrate-analog hexapeptidyl chloromethyl ketone (CMK) inhibitor, as well as from structural information derived from amodeled inhibitor, AG-7088 in the SCLpro active site. Two of these inhibitors are not only quite active against SARS-SCLpro, but also inhibit MHV (mouse hepatitis virus) and SARS-HCoV cell culture assays at 50 to 100 micromolar concentrations. We have also determined the X-ray structures of these inhibitors complexed with SARS-SCLpro at a resolution of 1.9 Angstroms. This work now forms the basis of our proposed studies in which the power of synthetic medicinal chemistry will be combined with crystallography and molecular modeling and utilized to further develop a new generation of structurally diverse and more potent inhibitors with clinical potential.