DEVELOPMENT OF A NOVEL CLASS OF ANTIBIOTICS AGAINST VIBRIO CHOLERAE NA+-NQR

新型抗霍乱弧菌 NA -NQR 抗生素的开发

• 批准号: 10367435
• 负责人: Oscar Juarez
• 金额: $ 55.41万
• 依托单位: ILLINOIS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-13 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10367435
• 关键词: Animal Model; Antibiotics; Antimalarials; Antipsychotic Agents; Automobile Driving; Bacterial Infections; Binding; Binding Sites; Biochemistry; Cell physiology; Cells; Cellular biology; Cholera; Communicable Diseases; Complex; Computer Analysis; Coupled; Crystallization; Data; Development; Diarrhea; Docking; Dose; Drug Design; Drug Efflux; Drug Targeting; Enzyme Inhibitor Drugs; Enzymes; Equilibrium; Evolution; Family; Foundations; Free Energy; Gastrointestinal Diseases; Generations; Growth; Human; Human Genome; Immune system; Infection; Intestines; Ions; Lead; Libraries; Life; Malaria; Mammalian Cell; Membrane; Metabolism; Methods; Microbe; Microbiology; Mitochondria; Modeling; Multi-Drug Resistance; Multienzyme Complexes; Multiple Bacterial Drug Resistance; NADH dehydrogenase (ubiquinone); Na(+)-K(+)-Exchanging ATPase; Nutrient; Oxidation-Reduction; Pathogenicity; Pattern; Performance; Persons; Pharmaceutical Chemistry; Pharmaceutical Preparations; Pharmacology; Phenothiazines; Phenotype; Physiology; Play; Predisposition; Process; Production; Property; Proteins; Psychoses; Reactive Oxygen Species; Regulation; Role; Rotation; Site; Sodium; Solid; Specificity; Structure; Testing; Toxic effect; Toxin; Ubiquinone; Vibrio cholerae; analog; bacterial metabolism; base; cell motility; design; drug development; functional group; gastrointestinal infection; human disease; improved; in vivo; inhibitor; iterative design; lead optimization; microbial; microorganism; mutant; novel; novel antibiotic class; novel therapeutics; pandemic disease; pathogen; pathogenic bacteria; pharmacophore; process optimization; resistance mechanism; resistant strain; respiratory; respiratory enzyme; scaffold; structural biology; uptake

PROJECT SUMMARY The sodium-dependent NADH: ubiquinone oxidoreductase (Na+-NQR) is the main ion transporter in hundreds of pathogenic bacteria, including Vibrio cholerae, the causal agent of cholera, a devastating gastrointestinal disease with a worldwide distribution that has developed multidrug-resistant phenotypes. Na+- NQR fulfills two essential roles in V. cholerae cell physiology, as a respiratory enzyme, providing energy to the cell, and as the main sodium pump, energizing the membrane and driving nutrient uptake, pH regulation, elimination of drugs, cell motility, secretion of toxins and other homeostatic processes. Na+-NQR is an optimal drug target due to its critical role in bacterial metabolism and because it is absent in mammalian cells. Moreover, Na+-NQR has unique structural motifs, not found in any human protein, which allow the discovery of drugs that can act specifically on this enzyme. In addition, Na+-NQR inhibitors could increase the susceptibility of V. cholerae to other drugs by de-energizing the membrane, and may be used in a combination dosing approach to rescue obsolete antibiotics. Our group has now identified two novel compound leads, ubiquinone analogs (UQAs) and phenothiazines, as inhibitors of this enzyme that are suitable for drug development. The three UQAs analogs characterized have antimalarial properties and show specific and potent inhibitory effects on Na+-NQR, with strong antibiotic activity against V. cholerae. These compounds not only abolish V. cholerae Na+-NQR enzymatic activity, but also trigger the overproduction of reactive oxygen species, which is lethal to microbes. The structures of these inhibitors and docking methods were used to identify the pharmacophore and the binding modes of the molecules in the UQ binding site, which allow us to pursue lead development to obtain inhibitors of high potency and specificity. In addition, we have identified three phenothiazine-like compounds with anti- psychotic properties that show potent inhibitory activity against Na+-NQR and that could be optimized into antibiotics. The main aim of this project is the development of a novel class of antibiotics to specifically target the Na+-NQR complex. The inhibitors that we have identified will be fully characterized, to understand their mechanism of action, binding sites, potency and antibiotic properties. Moreover, toxicity towards human cells and mitochondria, as well as their pharmacologic properties, will be assessed to evaluate the potential of these compounds to treat human infections. The data obtained from toxicity studies, enzymatic and microbiological characterizations will be used to guide the design and synthesis of analogs with high potency and low toxicity. Lead optimization will be carried out by our medicinal chemistry team guided by pharmacophore analysis, docking and binding free energy calculations. The structures of the newly-identified inhibitors will be used to build compound libraries carrying the active core with different substitution patterns, which will be iteratively screened and characterized. The data generated in this proposal is critical to the discovery of urgently-needed antibiotics with a new mechanism of action effective against V. cholerae and many other Na+-NQR bearing pathogens.

项目概要 钠依赖性 NADH：泛醌氧化还原酶 (Na+-NQR) 是体内主要的离子转运蛋白 数百种致病细菌，包括霍乱弧菌，它是霍乱的病原体，是一种毁灭性的疾病 胃肠道疾病在全球范围内分布，已形成多重耐药表型。钠+- NQR 在霍乱弧菌细胞生理学中发挥着两个重要作用，作为一种呼吸酶，为 细胞，并作为主要的钠泵，为膜提供能量并驱动营养吸收、pH 调节、 消除药物、细胞运动、毒素分泌和其他稳态过程。 Na+-NQR 是最佳的 药物靶点，因为它在细菌代谢中发挥关键作用，并且在哺乳动物细胞中不存在。而且， Na+-NQR 具有在任何人类蛋白质中都未发现的独特结构基序，这使得能够发现以下药物： 可以特异性地作用于这种酶。此外，Na+-NQR抑制剂可以增加V的敏感性。 通过使膜断电来将霍乱弧菌转变成其他药物，并可用于组合给药方法 抢救过期抗生素。我们的小组现已鉴定出两种新型化合物先导物，泛醌类似物 (UQA) 和吩噻嗪作为这种酶的抑制剂，适合药物开发。三个UQA 类似物具有抗疟特性，并对 Na+-NQR 显示出特异性和有效的抑制作用， 对霍乱弧菌具有很强的抗生素活性。这些化合物不仅消除霍乱弧菌 Na+-NQR 酶活性，还会引发活性氧的过量产生，这对微生物来说是致命的。 这些抑制剂的结构和对接方法用于鉴定药效基团和结合 UQ 结合位点的分子模式，使我们能够进行先导化合物开发以获得抑制剂 具有高效力和特异性。此外，我们还发现了三种吩噻嗪类化合物，具有抗 精神病特性，对 Na+-NQR 显示出有效的抑制活性，并且可以优化为 抗生素。该项目的主要目的是开发一类新型抗生素，专门针对 Na+-NQR 复合物。我们已经确定的抑制剂将被充分表征，以了解它们的作用 作用机制、结合位点、效力和抗生素特性。此外，对人体细胞的毒性 和线粒体及其药理学特性将被评估，以评估这些的潜力 治疗人类感染的化合物。从毒性研究、酶学和微生物学研究中获得的数据 表征将用于指导高效低毒类似物的设计和合成。 先导化合物优化将由我们的药物化学团队在药效团分析的指导下进行， 对接和结合自由能计算。新发现的抑制剂的结构将用于构建 携带具有不同取代模式的活性核心的化合物库，将被迭代筛选 并进行了表征。该提案中生成的数据对于发现急需的抗生素至关重要 具有有效对抗霍乱弧菌和许多其他带有 Na+-NQR 的病原体的新作用机制。