Yeast-based HTS Assay Technologies for Proteases

描述（由申请人提供）：基于酵母的蛋白酶HTS检测技术。蛋白质的蛋白水解加工是一种不可逆的翻译后修饰，对多种生物过程具有重要意义。因此，蛋白酶已成为多种人类疾病（包括炎症、传染病、神经退行性疾病、缺血性疾病和癌症）药物开发的有希望的靶点。开发使用纯化蛋白酶的高通量筛选（HTS）测定方法可能相对简单，也可能相当具有挑战性，特别是当需要多组分系统来实现蛋白酶激活时。此外，由于某些蛋白酶组的活性位点相似，化学抑制剂的选择性即使不是不可能实现，也可能是困难的，这突出表明需要替代筛选方法来识别针对蛋白酶上游激活剂的化合物，而不是直接抑制感兴趣的蛋白酶。我们建议以Caspases为原型，生成和优化细胞内蛋白酶的HTS系统。为此，我们设计了以酵母为基础的细胞系统，允许蛋白酶和蛋白酶激活蛋白在这些简单的真核生物中重组整个哺乳动物途径的组合中轻松表达。在整合到酵母系统的检测方法中有可切割报告基因激活因子，其中蛋白酶介导的切割激活转录因子。目标是：(1)设计多组分系统，重建哺乳动物蛋白酶在酵母中的激活途径；(2)调整必要的变量以达到hts质量的分析性能；(3)对基于酵母的多组分蛋白酶检测系统进行中试化学文库筛选，以确定命中率和测试可靠性；(4)开发筛选后命中反卷积和验证的二级分析策略和方法。此外，我们将通过将其应用于成熟的HTS活动来验证这种HTS技术，其中化合物将被鉴定和优化，选择性抑制上游Caspase-1激活物NLRC4 (Ipaf1； CLAN)，这是先天免疫的一个组成部分，也是宿主对细胞内细菌病原体反应的关键调节因子。公共卫生相关性：蛋白酶是切割其他蛋白质的蛋白质。这些酶在许多疾病中起着重要作用。因此，蛋白酶已成为药物发现的有希望的靶点，但获得选择性抑制剂往往具有挑战性。我们建议设计一种新技术，用于高通量筛选大量化学物质，以识别细胞内蛋白酶上游激活剂的化学调节剂。为了证明这一概念，我们将重点放在对炎症和传染病重要的蛋白酶上。

DESCRIPTION (provided by applicant): Yeast-based HTS Assay Technologies for Proteases. Proteolytic processing of proteins is an irreversible post-translational modification of importance for a wide-variety of biological processes. Consequently, proteases have emerged as promising targets for drug discovery for a wide variety of human diseases, including inflammation, infectious diseases, neurodegeneration, ischemic diseases, and cancer. Development of high throughput screening (HTS) assays using purified proteases can be relatively straightforward or it can be quite challenging, particularly when multi-component systems are required to achieve protease activation. Also, due to similarity of the active sites of some groups of proteases, selectivity of chemical inhibitors can be difficult if not impossible to achieve, highlighting the need for alternative screening methods for identifying compounds that target upstream activators of proteases rather than directly inhibiting the protease of interest. We propose to generate and optimize HTS systems for intracellular proteases, using Caspases as a prototype. For this purpose, we have devised yeast-based cellular systems that permit facile expression of proteases and protease-activating proteins in combinations that reconstitute entire mammalian pathways in these simple eukaryotes. Among the assay methods integrated into the yeast system are cleavable reporter gene activators, in which protease-mediated cleavage activates a transcription factor. The Aims are to: (1) Devise multi-component systems that reconstitute mammalian protease activation pathways in yeast; (2) Adjust the necessary variables to achieve HTS-quality assay performance; (3) Perform pilot chemical library screens of multi-component yeast-based protease assay systems to define hit-rates and test reliability; and (4) Develop secondary assay strategies and methods for post- screening hit deconvolution and validation. In addition, we will validate this HTS technology by applying it for a full-fledged HTS campaign in which compounds will be identified and optimized that selectively inhibit the upstream Caspase-1 activator NLRC4 (Ipaf1; CLAN), a component of innate immunity and critical regulator of host responses to intracellular bacterial pathogens. PUBLIC HEALTH RELEVANCE: Proteases are proteins that cleave other proteins. These enzymes play important roles in many diseases. Consequently, proteases have emerged as promising targets for drug discovery, but it can often be challenging to obtain selective inhibitors. We propose to devise a novel technology for high- throughput screening of large collections of chemicals for identifying chemical modulators of the upstream activators of intracellular proteases. For proof of concept, we focus on proteases important for inflammatory and infectious diseases.