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

• 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
• 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

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）：由恶性疟原虫疟原虫引起的热带疟疾每年造成高达300万人死亡。由于寄生虫会产生对大多数临床上可用药物的抗性，因此迫切需要新型的抗疟药。基于观察到，该酶中患有遗传缺乏症的人受到保护，可防止疟疾，葡萄糖 - 6-磷酸脱氢酶（G6PD）是抗疟药设计的新靶标。 G6PD催化了五磷酸五磷酸五磷酸途径的第一步，产生了NADPH，这是对红细胞（RBC）中氧化应激等效的重要减少。在RBC阶段，疟疾寄生虫易受氧化应激。天然发生的G6PD缺乏会导致缺乏减少的等效因素，氧化应激的增加，增强的寄生虫感染的RBC的吞噬作用，并因此，以保护疟疾。寄生虫感染的RBC中的NADPH由人类G6PD，但也由具有G6PD活性的寄生虫酶产生，称为恶性疟原虫葡萄糖-6-磷酸葡萄糖 - 磷酸 - 脱水酶-6-磷酸葡萄糖糖糖酸糖醇乳酸酸酯酶（Pfglupho）。我们假设抑制pfglupho并在一定程度上降低了疟疾发生的风险。到目前为止，探索G6PD和Pfglupho作为抗疟药靶标受到缺乏重组PFGLUPHO的限制。最近，我们的德国团队生产了第一个完整的重组PFGLUPHO。现在，我们旨在使用这种重组，纯蛋白来鉴定可能是新型和创新抗疟药的潜在候选抑制剂。在AIM 1中，我们将以毫克数量生产人类G6PD和Pfglupho。 AIM 2然后在已经建立的高通量筛选测定中使用这些蛋白质来鉴定酶抑制剂。在低微摩尔到纳摩尔浓度范围内活跃的化合物将在分离的酶上进行详细的动力学分析。 AIM 3遵循确定的抑制剂，并评估它们是否影响恶性疟原虫的生长和寄生虫血症，而无需在哺乳动物细胞中具有细胞毒性。由于G6PD缺乏症是针对疟疾寄生虫的可靠原理，并且由于寄生虫酶在结构和机械上与人宿主酶有所不同，因此Pfglupho是一个很好的药物靶标。我们旨在鉴定2-3种铅化合物，这些化合物在纳摩尔范围内活跃而没有明显的细胞毒性，可用于进一步的药物开发。这可能是一种高风险方法，因为不能保证高通量筛查和后续测定确定命中率。但是，我们已经确定了164种抑制细菌G6PD的化合物，并且我们预计Pfglupho和Human G6PD的命中率相似。这种方法有可能产生高影响结果。疟疾是全球最致命的疾病。疟疾寄生虫对大多数当前可用的药物产生抗性。因此，迫切需要新颖和创新的抗疟药。公共卫生相关性：热带疟疾每年造成高达300万人死亡。恶性疟原虫疟原虫会产生对大多数临床可用药物的抗药性。迫切需要新型的抗疟药。基于观察到，该酶缺乏症的人免受疟疾的侵害，葡萄糖-6-磷酸脱氢酶是抗疟药设计的新靶标。我们旨在鉴定在疟疾寄生虫和人类中在一定程度上抑制这种酶的化合物。我们的结果可能为开发新型抗疟药铺平了道路。