A chemical proteomic strategy to identify novel drug targets in Plasmodium falciparum and corresponding lead compounds for the development of new antimalarials

疟疾仍然是世界上发病率和死亡率的主要原因之一，每年造成100多万人死亡。鉴于寄生虫对常用药物的耐药性的广泛发展，有必要确定新的药物靶点并开发新的药效团。在本联合提案中，我们将利用一种新的化学蛋白质组学策略，称为基于活性的蛋白质谱（ABPP），以确定恶性疟原虫中对生存，生长或发病机制至关重要的新靶标，以及可以开发为抗疟疾的相应抑制剂。我们将筛选小型集中的药物库，如抑制寄生虫生长的天然产物激发的化合物，然后利用ABPP作为化学蛋白质组学方法来识别恶性疟原虫中相应的必需药物靶标。将克隆通过这些分析鉴定的选定生物学相关靶标，并表达重组蛋白。作为初步工作，我们已经鉴定了一些抑制寄生虫生长的β-内酯化合物，并鉴定了它们在寄生虫中的潜在蛋白酶靶标。将使用重组蛋白和靶向化合物进行详细的体外相互作用研究和酶活性抑制研究。这些化合物的衍生物将被设计用于鉴定具有更高亲和力结合/活性抑制和更高功效抑制寄生虫生长的分子。将进一步评估所选化合物在小鼠疟疾模型中抑制寄生虫生长的能力。

Malaria remains one of the leading causes of morbidity and mortality in the world resulting in over a million deaths every year. In view of the widespread development of drug resistance in the parasite against commonly used drugs, there is a necessity to identify new drug targets and develop new pharmacaphores. In the present joint proposal we will utilize a novel chemical proteomic strategy termed activity based protein profiling (ABPP) to identify new targets in P. falciparum that are either essential for survival, growth or pathogenesis together with their corresponding inhibitors that can be developed as anti-malarial. We will screen small focused libraries of drug like natural product inspired compounds that inhibit the parasite growth and then utilize ABPP as chemical-proteomic approach to identify and the corresponding essential drug targets in P. falciparum. Selected biologically relevant targets identified by these analyses will be cloned and recombinant proteins will be expressed. As preliminary work we have already identified some β-lactone compounds that inhibit parasite growth and also identified their potential protease targets in the parasite. Detailed in vitro interaction studies and enzyme activity inhibition studies will be carried out using the recombinant proteins and targeting compounds. Derivatives of these compounds will be designed to identify molecules of higher affinity binding/activity inhibition and higher efficacy to inhibit parasite growth. Selected compounds will be further assessed for their ability to inhibit growth of parasites in a mouse-malaria model.