Structure-based Drug Design for Smallpox Therapy

描述（由申请人提供）：真实世界条件的总和强烈表明，天花可以被用作生物恐怖主义的特别毁灭性武器。有一个迫切的医疗和国家需要设计一种新的抗天花治疗，并使其除了现有的预防措施，美国人口。我们提出的全面综合的“国家重点”计划直接满足RFA AI-03-017规定的目标，并专注于天花治疗的合理结构药物设计。我们开发天花治疗的战略是以开发唯一成功的选择性抗病毒治疗--艾滋病蛋白酶抑制剂“鸡尾酒”为指导的。天花病毒基因组编码两种蛋白酶（H1 L和K7 L），这两种蛋白酶都参与病毒蛋白前体的加工和病毒粒子的组装。我们的工作将产生第一个也是唯一一个适用于天花爆发/攻击的快速反应的蛋白酶抑制剂。参与这项工作的伯纳姆研究所科学家是唯一有资格成功完成该计划的人。我们的团队包括国内和国际知名的金属和半胱氨酸蛋白酶专家，国际公认的结构生物学家和药物设计前沿专家。我们将使用几个独立的，但重叠的管道，以产生抑制剂，并确保该计划的整体成功。我们的目标是：（I）表达、纯化和表征牛痘/天花的重组金属蛋白酶H1 L和半胱氨酸蛋白酶K7 L，（II）鉴定重组蛋白酶的最佳肽底物，然后将这些底物衍生为前导肽拮抗剂，（III）通过筛选组合化学文库鉴定天花蛋白酶的药物样小分子抑制剂，（IV）确定，在原子分辨率水平上，单个H1 L和K7 L蛋白酶的结构以及它们与先导物拮抗剂和最佳肽底物结合的结构，（V）通过迭代的基于合理结构的药物设计，增加所选药物先导物的选择性、效力和安全性，（VI）在体外和基于细胞的牛痘病毒复制测定中检查候选药物的功效和安全性。当达到适当的基准时，候选药物将被交付给政府，以继续进行涉及天花病毒的测试和改进。

DESCRIPTION (provided by applicant): The sum of the real-world conditions argues strongly that smallpox could be used as a particularly devastating weapon of bioterrorism. There is an urgent medical and national need to design a novel anti-smallpox therapy and to make it available in addition to the existing preventive measures, to the US population. The comprehensive and integrated "key national priority" program we are proposing meets directly the stated objectives set forth by RFA AI-03-017 and is focused on a rational structure-based drug design for a smallpox therapy. Our strategies towards developing a smallpox therapy are guided by the development of the only successful and selective anti-viral therapy, the AIDS protease inhibitor "cocktail". There are only two proteinases (H1L and K7L) encoded by the variola genome, both of which are involved in the processing of viral protein precursors and virion assembly. Our work will generate the first and the only set of protease inhibitors applicable as a rapid response to a smallpox outbreak/attack. The Burnham Institute scientists participating in this effort are uniquely qualified to accomplish the program successfully. Our team includes nationally and internationally known experts on metallo- and cysteine proteinases, internationally recognized structural biologists, and experts on the cutting edge of drug design. We will use several independent, albeit overlapping pipelines, to generate the inhibitors and to ensure the overall success of the program. Our aims are: (I) to express, purify and characterize the recombinant metalloproteinase H1L and the cysteine proteinase K7L of vaccinia/variola, (lI) to identify optimal peptide substrates for the recombinant proteinases and then to derivatize these substrates into lead peptidic antagonists, (III) to identify drug-like small molecule inhibitors of the variola proteases by screening combinatorial chemical libraries, (IV) to determine, at the atomic resolution level, the structure of the individual H1L and K7L proteases and their structures bound to lead antagonists and optimal peptide substrates, (V) to increase, through iterative rational structure-based drug design, the selectivity, potency, and safety of the selected drug leads, (VI) to examine the efficacy and safety of the drug candidates in vitro and in cell-based assays of vaccinia viral replication. When appropriate benchmarks are met, the drug candidates will be delivered to the government for continued testing and refinement involving the variola virus.