Discovery of West Nile Virus Protease Inhibitors

描述(申请人提供)：目前在美国大陆流行的西尼罗河病毒株比最初在非洲分离的病毒毒力更强，被NIAID归类为B类优先病原体。在短短六年内，它已经蔓延到整个美国大陆，导致高发病率和死亡率。去年，在向疾控中心报告的2539例专利中，近一半的专利有神经侵入性症状。目前还没有对抗西尼罗河病毒感染的疫苗或药物，只有对症治疗。我们的最终目标是开发一种预防或治疗这种疾病的方法。为了实现这一点，我们将开发抑制西尼罗河病毒NS3蛋白酶的化合物的鉴定方法。蛋白水解酶是病毒成熟的关键酶，抑制黄病毒蛋白水解酶可显著减少病毒复制。基于结构的药物设计将提供一条快速获得有效的和病毒特异性的蛋白酶抑制剂的途径。在存在和不存在已知的基于多肽的抑制剂的情况下，将确定该蛋白水解酶的晶体结构，以确定其活性部位。我们将用化学库对活性部位进行虚拟筛选。将仔细注意文库的组成，以确保丰富各种具有药理活性的类似铅的化合物。将开发一种具有广泛灵敏度的生化分析方法，可用于从我们的虚拟屏幕识别弱结合的初始点击，以及在我们在未来的研究中优化这些点击时测量抑制的微小变化。在虚拟屏幕中选择的在生化分析中具有活性的化合物将与蛋白酶共结晶，使我们清楚地了解化合物是否适合活性部位。这将使我们能够从活性化合物中快速确定最佳候选化合物，并在第二阶段的研究中进行后续优化。

DESCRIPTION (provided by applicant): The strain of West Nile virus now endemic in the continental United States is more virulent than the virus originally isolated in Africa and is classified as a category B priority pathogen by the NIAID. In only six years, it has spread throughout the continental United States, resulting in high morbidity and mortality. Last year, of the 2,539 cases reported to the CDC, nearly half of the patents had neuroinvasive symptoms. There is currently no vaccine or drug that combats the West Nile virus infection and only symptomatic treatment is available. Our ultimate goal is to develop a prophylactic or therapeutic treatment for this disease. To accomplish this, we will develop methods for the identification of compounds that inhibit the West Nile viral NS3 protease. The protease is a key enzyme in viral maturation and inhibition of flavivirus protease has been shown to dramatically reduce viral replication. Structure based drug design will provide a rapid path to potent and virus specific protease inhibitors. The crystal structure of this protease in the presence and absence of known peptide based inhibitors will be determined in an effort to characterize the active site. We will virtually screen the active site with a chemical library. Careful attention will be made to the composition of the library to ensure enrichment with diverse, pharmacologically active, lead-like compounds. A biochemical assay will be developed that has a wide range of sensitivity that can be used in the identification of weak binding initial hits from our virtual screen as well as to measure small changes in inhibition as we optimize these hits in future research. Compounds that are selected in the virtual screen and are active in the biochemical assay will be cocrystallized with the protease, giving us a clear picture of the compound's fit into the active site. This will position us to rapidly identify the best candidates from the active compounds and subsequent optimization in phase 2 research.