Design & Synthesis of SARS Protease Inhibitors

本项目的主要目的是利用我们广泛的初步结果，设计和开发用于严重急性呼吸综合征（SARS）治疗干预的SCLpro抑制剂。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。到2003年7月，这一流行病已经影响了8000多名报告的个人，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， 是由多聚蛋白通过蛋白水解加工产生的，所述蛋白水解加工由被称为3C样蛋白酶（SCLpro）的33.1-kD HCoV 229 E主蛋白酶进行，并且该SCLpro蛋白酶的活性对于冠状病毒复制是关键的。因此，这种蛋白酶被认为是SARS和相关感染药物开发的一个有吸引力的靶标。在前期工作中，我们根据SCLpro的X-射线晶体结构、猪传染性胃肠炎（冠状）病毒相关酶（TGEV Mpro）的X-射线晶体结构和底物类似物六肽基氯甲基酮（CMK），设计并合成了一系列SCLpro蛋白酶抑制剂 抑制剂，以及来自SCLpro活性位点中的模型化抑制剂AG-7088的结构信息。这些抑制剂中的两种不仅对SARS-SCLpro相当有效，而且在50至100微摩尔浓度下抑制MHV（小鼠肝炎病毒）和SARS-HCoV细胞培养测定。我们还确定了这些抑制剂与SARS-SCLpro复合的X射线结构，分辨率为1.9埃。这项工作现在形成了我们提出的研究的基础，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化和更有效的抑制剂。

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.