New tools for antimalarial target identification

抗疟靶点识别的新工具

• 批准号: 10350687
• 负责人: Kathryn Jean Wicht
• 金额: $ 14.12万
• 依托单位: UNIVERSITY OF CAPE TOWN
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-22 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10350687
• 关键词: Academic Medical Centers; Amodiaquine; Antimalarials; Artemisinins; Binding; Biological Assay; Cambodian; Cells; Characteristics; Chemicals; Clinical; Collection; Computing Methodologies; Data; Databases; Development; Docking; Drug Metabolic Detoxication; Endocytosis; Erythrocytes; Exhibits; Falciparum Malaria; Genes; Grant; Hematin; Heme; Hemoglobin; Investigation; Laboratories; Libraries; Literature; Malaria; Maps; Measurement; Measures; Mefloquine; Methods; Modeling; Molecular; Multi-Drug Resistance; National Center for Advancing Translational Sciences; New York; Parasites; Pathway interactions; Pharmaceutical Preparations; Pharmacologic Substance; Pharmacology; Phenotype; Plasmodium falciparum; Predisposition; Prevalence; Process; Proteins; Proteolysis; Publications; Publishing; Refractory; Reporting; Research; Resistance; Role; Series; Site; Solvents; South Africa; Testing; Training; United States National Institutes of Health; Universities; Validation; Villus; Work; analytical method; benflumetol; design; drug discovery; experience; experimental study; hemozoin; high throughput screening; improved; in silico; inhibitor; insight; kinetic model; liquid chromatography mass spectrometry; mathematical model; mutant; novel; overexpression; pathogen; plasmepsin; predictive modeling; pyridine; pyronaridine; resistant Plasmodium falciparum; screening; small molecule libraries; success; tool; virtual laboratory; virtual screening

Target identification is a vital step in the drug discovery process and represents a substantial hurdle to further development when large numbers of hit compounds are identified by high throughput phenotypic screening. This problem is especially challenging in the case of antimalarial drug discovery because of the prevalence of unconventional targets such as hemozoin, the formation of which is thought to be inhibited by nearly half the clinical antimalarials and many experimental compounds. A key feature of the success of these drugs is that hemozoin is derived from host hemoglobin and is therefore not mutable, thereby reducing the ability of P. falciparum to acquire resistance. Prior studies have shown that target identification is complicated by the fact that the ability to inhibit abiotic synthetic hemozoin (-hematin) formation is a necessary, but not sufficient predictor of hemozoin inhibition in Plasmodium falciparum malaria parasites and conversely, decreased hemozoin formation in the parasite is not itself confirmation of direct inhibition of hemozoin formation. We hypothesize that direct measurement of increased unsequestered heme together with decreased hemozoin in the intra-erythrocytic parasite is the most consistent method of identifying hemozoin inhibitors and that the latter cause characteristic perturbations of the heme detoxification pathway that can be exploited in target deconvolution. We further hypothesize that these inhibitors occupy a distinct region of chemical space that can be mapped in silico. To achieve our objectives, the following specific aims are proposed: 1) Develop generalizable methods to measure and detect hemozoin inhibition in Plasmodium falciparum; 2) Use in silico methods to map hemozoin inhibition in chemical space; and 3) Develop a model of the full heme detoxification pathway. To realize these aims, the research will be conducted as a collaborative and synergistic project between Timothy Egan at the University of Cape Town (UCT), Katherine de Villiers at Stellenbosch University (SU), South Africa and David Fidock at the Columbia University Medical Center (CUMC), New York, NY. Generalizable analytical methods for measuring unsequestered heme will be developed at UCT and transferred to CUMC for investigation of compound collections available at that site. A laboratory strain expected to exhibit universally reduced susceptibility to hemozoin inhibitors will be generated at CUMC. In silico methods for mapping -hematin inhibitors will be developed at SU and screening via molecular docking performed at UCT. Validation of these methods will take place at UCT and SU. The input data for modeling the heme detoxification pathway will be collected at UCT, while the mathematical model of this pathway will be developed at SU. Validation of the model will be conducted at UCT and CUMC. We expect that this work will transform our ability to discern the role of hemoglobin degradation and hemozoin synthesis in the mode of action of antimalarials, and provide vital tools to identify novel inhibitors that are refractory to a rapid gain of resistance and can treat multidrug-resistant P. falciparum malaria.

靶标鉴定是药物发现过程中的重要步骤，并且代表了进一步研究的实质性障碍。 当通过高通量表型筛选鉴定大量命中化合物时，这 在抗疟药物发现方面，这个问题特别具有挑战性，因为疟疾的流行， 非传统的目标，如疟原虫色素，其形成被认为是抑制了近一半的 临床抗疟药和许多实验性化合物。这些药物成功的一个关键特征是， 疟原虫色素来源于宿主血红蛋白，因此是不可突变的，从而降低了P. 获得抵抗力。先前的研究表明，目标识别是复杂的事实， 抑制非生物合成血红素（血红素）形成的能力是必要的，但不是充分的， 恶性疟原虫色素抑制的预测因子，反之， 寄生虫中疟原虫色素的形成本身并不证实疟原虫色素形成的直接抑制。我们 假设直接测量未螯合血红素增加和疟原虫色素减少， 红细胞内寄生虫是鉴定疟原虫色素抑制剂的最一致的方法， 引起血红素解毒途径的特征性扰动，可用于靶向 反卷积我们进一步假设，这些抑制剂占据了一个独特的化学空间区域， 在silico中映射。为了实现我们的目标，提出了以下具体目标：1）发展 测量和检测疟原虫色素对恶性疟原虫抑制作用的通用方法; 2）计算机模拟使用 在化学空间中映射血红素抑制的方法;以及3）开发完全血红素解毒的模型 通路为了实现这些目标，研究将作为一个合作和协同项目进行， 蒂莫西埃根在开普敦大学（UCT），凯瑟琳德维利尔斯在斯泰伦博斯大学（SU），南 非洲和大卫菲多克在哥伦比亚大学医学中心（CDC），纽约，纽约。可泛化 测量未螯合血红素的分析方法将在UCT开发，并转移到CNOC， 对现场可获得化合物集合进行调查。一种实验室菌株， 对疟原虫色素抑制剂的敏感性降低将产生于100 ℃。用于映射血红素的计算机模拟方法 将在SU开发抑制剂，并在UCT通过分子对接进行筛选。验证这些 方法将在UCT和SU进行。用于血红素解毒途径建模的输入数据将是 收集在UCT，而这一途径的数学模型将在SU开发。验证的模型 将在UCT和CQC进行。我们希望这项工作将改变我们辨别 血红蛋白降解和疟原虫色素合成的抗疟药的作用模式，并提供重要的工具， 以确定新的抑制剂，是难治性的快速获得的阻力，并可以治疗多药耐药的P。 恶性疟疾