Bacterial-type hexokinase (HK) in the opportunistic parasite Cryptosporidium parv

描述：小隐孢子虫是一种AIDS-OI病原体和B类病原体。它是一种重要的水和食物传播的原生动物寄生虫，可引起人类和动物严重的水样腹泻。目前，在美国，只有一种药物（即nitazoxanide [NTZ]）被批准用于治疗免疫功能正常（但非免疫功能低下）的隐孢子虫病患者。然而，NTZ对隐孢子虫病并不是100%有效。隐孢子虫也可能产生潜在的耐药性，类似于疟疾寄生虫和球虫的耐药性问题。因此，迫切需要开发新的抗隐孢子虫药物。我们这项转化研究的长期目标是表征小弧菌糖酵解途径中必需酶的分子和生化特征，作为潜在的药物靶点。由于小孢子虫完全依赖糖酵解来获取能量，我们假设在糖酵解途径中负责反应进入步骤的细菌型CpHK可能作为该寄生虫的合理药物靶点。为了验证这一假设，我们将进行实验来表征CpHK的生化特征，并通过化合物文库的HTS鉴定CpHK抑制剂用于未来的药物开发，表征顶部命中的抑制动力学，并在体外测试它们对小孢子虫生长的功效。这个探索性/发展性R21项目的主要目标是确定抑制CpHK的hit

DESCRIPTION: Cryptosporidium parvum is an AIDS-OI pathogen and Category B agent. It is a significant water- and food-borne protozoan parasite that can cause severe watery diarrhea in humans and animals. Currently, only a single drug (i.e., nitazoxanide [NTZ]) is approved for treating cryptosporidiosis in immunocompetent (but not immunocompromized) patients in the United States. However, NTZ is not 100% effective against cryptosporidiosis. Potential drug resistance may also be developed in Cryptosporidium, similar to the drug resistance problem in malarial parasites and coccidia. Therefore, there is an urgent need to develop new anti-Cryptosporidium drugs. Our long-term goal of this translational research is to characterize the molecular and biochemical features of the essential enzymes in the C. parvum glycolytic pathway as potential drug targets. Because C. parvum relies solely on glycolysis for its energy, we hypothesize that the bacterial-type CpHK responsible for the entry step of reaction in the glycolytic pathways could serve as rational drug targets in this parasite. To test the hypothesis, we will perform experiments to characterize the biochemical features of CpHK and identify CpHK inhibitors for future drug development via HTS of compound libraries, characterize the inhibitory kinetics of top hits, and test their efficacies against C. parvum growth in vitro. The major goal of this exploratory/developmental R21 project is to identify hits that inhibit both CpHK enzyme activity and the parasite growth in vitro, which would produce conclusive data for further studying the mechanism of inhibition, structure-activity relationship, and to synthesize new analogs of hits for lead optimization, as well as to assess the efficacies of hits and leads agains cryptosporidial infection in animal models.