嚴重急性呼吸道症候群3CL蛋白酶之生成與以結構為基礎之藥物設計

Abstract

嚴重急性呼吸道症候群為由一新型人類冠狀病毒 (SARS-CoV) 所感染且快速傳染的疾病。此病毒在宿主體內之成熟需藉由一主要蛋白酶—3C-like (3CL)蛋白酶。3CL蛋白酶主要負責的工作為剪切病毒基因所轉錄出來的蛋白鍊並促使3CL蛋白酶本身之熟成 (二聚體的形成)進而啟動病毒基因的複製作用。因此3CL蛋白酶成為對抗病毒之藥物設計時的重要標的物。本論文包含了此蛋白酶之蛋白質晶體結構及一與產物相結合之C145A突變株之結構。藉由此產物結合之結構與一系列研究方法，推論出3CL蛋白質二聚體形成之模式，同時透過基質序列之專一性作為對抗此一冠狀病毒之藥物設計基礎。最後，利用rhinovirus藥物-AG7088作為開端進行對抗SARS 藥物設計。本論文結合了生物資訊之基質專一性資料，酵素抑制及病毒抑制細胞實驗加上四個抑制劑與蛋白酶之蛋白質結晶結構設計出一個能有效對抗SARS病毒之抑制劑-TG-0205221。最後，建立了一個快速、有效、且節省成本之以結構為基礎之藥物設計模式。

Severe acute respiratory syndrome (SARS) is an emerging infectious disease caused by a novel human coronavirus. Viral maturation requires a main protease (3CLpro) to cleave the virus-encoded polyproteins. In this study, the dimeric 3-D structure of the C145A mutant protease shows that the active site of one protomer binds with the C-terminal six amino acids of the protomer from another asymmetric unit, mimicking the product-bound form and suggesting a possible mechanism for maturation. This product-bound structure also provides insights into the maturation process of the SARS 3CLpro from the polyprotein and design of new structure-based inhibitors. For structure-based drug design, AG7088 (an anti-rhinivirus drug) is the lead compound for the design of anti-SARS 3CL protease inhibitor. Substrate based bioinformatics, enzyme based, anti-viral cell-based assay and four inhibitor-protease complex crystal structures established a potent anti-SARS protease inhibitor-TG-0205221. Finally, fast, efficient and cost-saving chemical synthesis strategy for structure based anti-viral protease drug design is established.