Identification of G6PD inhibitors for the development of novel antimalarial drugs

鉴定 G6PD 抑制剂用于开发新型抗疟药物

基本信息

批准号：
7644705
负责人：
Lars Bode
金额：
$ 19.35万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-08-01 至 2011-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7644705
关键词：
Abbreviations Affect Antimalarials Biological Assay Cessation of life Collaborations Combined Modality Therapy Communicable Diseases Development Disease Drug Delivery Systems Drug Design Enzyme Inhibitor Drugs Enzyme Inhibitors Enzymes Erythrocytes Escherichia coli Future Genetic German population Glucose-6-Phosphate Glucosephosphate Dehydrogenase Glucosephosphate Dehydrogenase Deficiency Growth Human Infection Kinetics Lead Malaria Mammalian Cell NADP Oxidative Stress Parasitemia Parasites Parents Pentosephosphate Pathway Phagocytosis Pharmaceutical Preparations Plasmodium falciparum Play Proteins Recombinants Research Project Grants Resistance Resistance development Risk Role Staging Testing United States National Institutes of Health base cytotoxic cytotoxicity drug development fighting follow-up high risk high throughput screening inhibitor/antagonist innovation novel overexpression programs public health relevance tissue culture

项目摘要

DESCRIPTION (provided by applicant): Tropical malaria, caused by the parasite Plasmodium falciparum, is responsible for up to three million deaths each year. Since the parasite develops resistance against most clinically available drugs, novel antimalarial drugs are urgently needed. Glucose-6-phosphate dehydrogenase (G6PD) is a novel target for antimalarial drug design based on observations that humans with a genetic deficiency in this enzyme are protected against malaria. G6PD catalyses the initial step of the pentose phosphate pathway, yielding NADPH, an essential reducing equivalent to detoxify oxidative stress in red blood cells (RBCs). The malaria parasite is susceptible to oxidative stress in the RBC stage. Naturally occurring G6PD deficiency leads to a lack of reducing equivalents, an increase in oxidative stress, enhanced phagocytosis of parasite-infected RBCs, and, as a consequence, to a protection against malaria. NADPH in parasite-infected RBCs is generated by human G6PD but also by a parasite enzyme with G6PD activity, called P. falciparum glucose-6-phosphate-dehydrogenase-6- phosphogluconolactonase (PfGluPho). We hypothesize that inhibiting PfGluPho and, to a certain extent, human G6PD reduces the risk of developing malaria. So far, exploring G6PD and PfGluPho as antimalarial drug targets was limited by a lack of recombinant PfGluPho. Very recently our German team produced the first complete and functional recombinant PfGluPho. We now aim at using this recombinant, pure protein to identify inhibitors which could be potential candidates for novel and innovative antimalarial drugs. In AIM 1 we will produce human G6PD and PfGluPho in mg quantities. AIM 2 then uses these proteins in already established high-throughput screening assays to identify enzyme inhibitors. Compounds active in the low micromolar to nanomolar concentration range will be subject to detailed kinetic analyses on isolated enzymes. AIM 3 follows up on the identified inhibitors and assesses whether they impact P. falciparum growth and parasitemia without being cytotoxic in mammalian cells. Since G6PD deficiency is a proven principle against malarial parasites and since the parasite enzyme differs structurally and mechanistically from the human host enzyme, PfGluPho is an excellent drug target. We aim at identifying 2-3 lead compounds which are active in the nanomolar range without significant cytotoxicity, which can be used for further drug development. This may be a high risk approach since it is not guaranteed that high-throughput screening and follow-up assays identify a hit. However, we have already identified 164 compounds that inhibit bacterial G6PD, and we anticipate a similar hit rate for PfGluPho and human G6PD. This approach has the potential to generate high impact results. Malaria is the most deadly disease worldwide. The malaria parasite develops resistance to most of the currently available drugs. Thus, novel and innovative antimalarial drugs are desperately needed. PUBLIC HEALTH RELEVANCE: Tropical malaria is responsible for up to three million deaths annually. The malaria parasite Plasmodium falciparum develops resistances against most clinically available drugs. Novel antimalarial drugs are urgently needed. Glucose-6-phosphate dehydrogenase is a novel target for antimalarial drug design based on observations that humans with a deficiency in this enzyme are protected from malaria. We aim at identifying compounds that inhibit this enzyme both in malaria parasites and, to a certain extent, in humans. Our results may pave the way for the development of novel antimalarial drugs.

描述（由申请人提供）：热带疟疾由恶性疟原虫引起，每年导致多达 300 万人死亡。由于寄生虫对大多数临床可用药物产生耐药性，因此迫切需要新型抗疟药物。 6-磷酸葡萄糖脱氢酶 (G6PD) 是一种抗疟药物设计的新靶标，其基础是观察到具有这种酶遗传缺陷的人类可以免受疟疾的侵害。 G6PD 催化磷酸戊糖途径的第一步，产生 NADPH，这是一种重要的还原剂，可解毒红细胞 (RBC) 中的氧化应激。疟原虫在红细胞阶段容易受到氧化应激的影响。自然发生的 G6PD 缺乏会导致还原当量缺乏、氧化应激增加、寄生虫感染红细胞的吞噬作用增强，从而预防疟疾。寄生虫感染的红细胞中的 NADPH 由人类 G6PD 产生，但也由具有 G6PD 活性的寄生虫酶（称为恶性疟原虫葡萄糖-6-磷酸-脱氢酶-6-磷酸葡萄糖酸内酯酶 (PfGluPho)）产生。我们假设抑制 PfGluPho 以及在一定程度上抑制人类 G6PD 可以降低患疟疾的风险。迄今为止，由于缺乏重组 PfGluPho，探索 G6PD 和 PfGluPho 作为抗疟药物靶点受到限制。最近，我们的德国团队生产出了第一个完整且功能性的重组 PfGluPho。我们现在的目标是利用这种重组的纯蛋白来鉴定抑制剂，这些抑制剂可能成为新型和创新性抗疟药物的潜在候选者。在 AIM 1 中，我们将生产毫克量的人 G6PD 和 PfGluPho。然后，AIM 2 在已经建立的高通量筛选测定中使用这些蛋白质来识别酶抑制剂。在低微摩尔至纳摩尔浓度范围内具有活性的化合物将对分离的酶进行详细的动力学分析。 AIM 3 对已确定的抑制剂进行跟踪，并评估它们是否会影响恶性疟原虫生长和寄生虫血症，而不会对哺乳动物细胞产生细胞毒性。由于 G6PD 缺乏已被证明是对抗疟疾寄生虫的原理，并且由于寄生虫酶在结构和机制上与人类宿主酶不同，因此 PfGluPho 是一个极好的药物靶点。我们的目标是鉴定 2-3 个先导化合物，它们在纳摩尔范围内具有活性，且没有显着的细胞毒性，可用于进一步的药物开发。这可能是一种高风险的方法，因为不能保证高通量筛选和后续分析能够识别命中。然而，我们已经鉴定出 164 种抑制细菌 G6PD 的化合物，并且我们预计 PfGluPho 和人类 G6PD 的命中率相似。这种方法有可能产生高影响力的结果。疟疾是全世界最致命的疾病。疟疾寄生虫对大多数目前可用的药物产生了耐药性。因此，迫切需要新型和创新的抗疟药物。公共卫生相关性：热带疟疾每年导致多达 300 万人死亡。疟原虫恶性疟原虫对大多数临床可用药物产生耐药性。迫切需要新型抗疟药物。葡萄糖-6-磷酸脱氢酶是抗疟药物设计的新靶点，其基础是观察到缺乏这种酶的人类可以免受疟疾的侵害。我们的目标是鉴定在疟疾寄生虫中以及在一定程度上在人类中抑制这种酶的化合物。我们的结果可能为新型抗疟药物的开发铺平道路。