Targeting trypanosomatid deoxyhypusine synthase

项目描述。 锥虫寄生虫是人类非洲锥虫病(HAT)的病原体， 利什曼病和恰加斯病，都被世界卫生组织列为被忽视的热带病 (NTDS)。总共有1800万至2000万人感染了这种寄生虫，但药物疗法 仍然不足以应对所有三种疾病。发现一种可以用来对付所有人的药物靶点 三种寄生虫虽然对宿主没有毒性，但将提供一种强有力的新方法 与这些疾病作斗争。真核生物普遍需要一种名为eIF5A的翻译因子来促进细胞生长。 要发挥活性，eIF5A必须在保守的赖氨酸上进行翻译后修饰，才能产生 一种名为苏氨酸的新型氨基酸。脱氧亚硫氨酸催化eIF5A的亚精氨酸修饰 以精胺为底物的合成酶(DHS)。DHS是所有真核生物中的一种必不可少的酶，包括 锥虫。我们之前证明了锥虫和内阿米巴的DHS 独特地进化到需要在两个相似的基因产物之间形成异四聚体才能产生 有活性的酶。这些寄生虫DHSS的这种不寻常的配置表明，可能是可行的 找出不抑制人类DHS的寄生虫酶的选择性抑制剂。这样做的目的是 建议确定DHS的类药物抑制剂是否对锥虫酶具有选择性 可以被识别，如果是的话，在HAT治疗的主导优化计划期间推进它们。 在这项提案的R21阶段，我们计划开发一种高通量筛选(HTS)兼容分析 并利用本方法筛选UT Southwest 200,000化合物文库。 布鲁赛DHS抑制剂。我们将对已识别的抑制剂进行HIT验证，并确定 与人类DHS相比，已鉴定的抑制剂显示出良好的选择性。如果锥虫特异的国土安全部 与我们计划的R33阶段相比，可以确定具有良好类药物特性的抑制剂 至少一个具有适当属性的系列的优化将被推进 帽子的处理。已确定的DHS抑制剂也将在HIT验证期间的不同阶段进行测试 并针对克氏锥虫和利什曼原虫进行优化，以确定它们是否有可能成为 被开发为治疗所有三种锥虫疾病的广谱疗法。

Project Description. Trypanosomatid parasites are the causative agents of human African trypanosomiasis (HAT), Leishmaniasis and Chagas disease, all of which are listed by the WHO as Neglected tropical diseases (NTDs). Collectively 18-20 million people are infected with one of these parasites, yet drug therapies remain inadequate for all three diseases. Discovery of a drug-target that could be exploited against all three parasites, while not showing toxicity against the host, would provide a robust new approach to combat these diseases. Eukaryotes universally require a translation factor called eIF5A for cell growth. To be active eIF5A must be post-translationally modified on a conserved lysine reside to generate a novel amino acid called hypusine. The hypusine modification of eIF5A is catalyzed by deoxyhypusine synthase (DHS) using spermidine as a substrate. DHS is an essential enzyme in all eukaryotes including the trypanosomatids. We previously demonstrated that DHS from trypanosomatids and Entamoeba have uniquely evolved to require heterotetramer formation between two paralogous gene products to generate the active enzyme. This unusual configuration of these parasite DHSs suggests that it may be feasible to identify selective inhibitors of the parasite enzymes that don't inhibit human DHS. The goal of this proposal is to determine if drug-like inhibitors of DHS that are selective for the trypanosomatid enzymes can be identified and if so to advance them during a lead optimization program for the treatment of HAT. In the R21 phase of this proposal we plan to develop a high throughput screen (HTS) compatible assay for T. brucei DHS and to use this assay to screen the UT Southwestern 200,000 compound library for T. brucei DHS inhibitors. We will perform hit validation on identified inhibitors and determine if the identified inhibitors show good selectivity versus human DHS. If trypanosomatid specific DHS inhibitors with good drug like properties can be identified than in the R33 phase of the proposal we plan a hit to lead optimization of at least one series with appropriate properties to be advanced for the treatment of HAT. Identified DHS inhibitors will also be tested at various stages during hit validation and lead optimization against T. cruzi and Leishmania to determine if they have the potential to be developed as a broad-spectrum treatment for all three trypanosomatid-based diseases.