Development of Selective Ribosomal P-site Inhibitors

选择性核糖体 P 位点抑制剂的开发

• 批准号: 9219231
• 负责人: Ryan Edward Looper
• 金额: $ 37.8万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-12-21 至 2020-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9219231
• 关键词: Address; Amination; Amines; Anti-Bacterial Agents; Antibiotics; Antimicrobial Resistance; Bacteria; Bacterial Proteins; Binding; Binding Sites; Biological Availability; Cations; Cells; Chemical Structure; Clinical; Collaborations; Combined Antibiotics; Crystallization; Cytosine; Development; Elements; Engineering; Equilibrium; Escherichia coli; Eukaryota; Eukaryotic Cell; Evaluation; Family; Genus Mycobacterium; Glutamates; Gram-Negative Bacteria; Guanidines; Guanine; Hexoses; Hospitals; Hybrids; Hydrogen Bonding; Interruption; Klebsiella pneumonia bacterium; Laboratories; Lead; Lethal Dose 50; Medical; Modification; Mycobacterium tuberculosis; Natural Products; New Agents; Oral; Peptidyltransferase; Pharmaceutical Chemistry; Pharmaceutical Preparations; Proline; Property; Protein Biosynthesis; Reporting; Resistance; Resolution; Ribosomal Proteins; Ribosomes; Safety; Site; Structure; Tail; Therapeutic; Time; Toxic effect; Transfer RNA; Translations; Tuberculosis; Work; amino group; analog; antimicrobial drug; bacterial resistance; base; carbapenem resistance; community setting; compound 30; cytotoxicity; global health; hydroxyl group; improved; inhibitor/antagonist; insight; methicillin resistant Staphylococcus aureus; mimetics; new therapeutic target; novel; novel therapeutics; pathogen; programs; resistant strain; scaffold; success; systemic toxicity

Project Summary The long-term objective of this project is to develop a new class of broad spectrum antibiotics, focused on Gram-negative bacteria and tuberculosis. In addition, the proposed project will teach how to optimize inhibitors of the prokaryotic ribosome by defining critical interactions only possible in bacteria. Inspired by a natural product, this class targets an unexploited binding site of the bacterial ribosome. With increasing reports of resistance to frontline antibacterial therapies, there is a critical need for new agents, yet very little can be found in the development pipeline. As a result, any new therapeutic that targets Gram-negative bacteria and/or tuberculosis will address an unmet medical need. A viable approach to discover new therapeutic leads is re-evaluation of existing, but under-scrutinized classes of natural products. Through this approach a natural product scaffold was identified as a lead for a program directed toward antibiotics for tuberculosis. Initial evaluation of activity against other bacteria indicated that the antibacterial spectrum was limited to Mycobacterium spp. However, based on the chemical structure and related compounds, we expected to be able to generate analogs with more broad spectrum activity. In collaboration with Tom Steitz's lab at Yale, the structure of the initial scaffold and two analogues bound to the ribosome were recently solved. The structural studies revealed that the natural product lead and analogues bind to a highly conserved region of the peptidyl transferase center (PTC) in a manner that appears to convey prokaryotic selectivity and which has not been exploited in current therapeutics. Targeting this highly conserved region is expected to lead to slow rates of resistance. This structural information was used to generate two more potent analogues with favorable physiochemical properties. In a very preliminary SAR campaign of ~30 compounds, we re-engineered a portion of our lead scaffold for both synthetic simplicity and stability to provide two analogs that introduce activity beyond Mtb, to MRSA, E. coli and K. pneumoniae (including a carbapenem-resistant strain), and do not exhibit cytotoxicity to eukaryotic cells (IC50 >100 µM). This project will explore and further define critical binding interactions for inhibitors to the bacterial ribosome that impart selectivity for inhibiting bacterial protein synthesis and broad spectrum antibacterial activity, while maintaining the lack of mammalian cytotoxicity. Aim 1 will expound on our hypothesis for how compounds can selectively bind to prokaryotic ribosomes at an undrugged site. If our hypothesis is correct, these inhibitors will not be active against mammalian ribosomes, thereby mitigating limitations of other ribosome-targeting antibiotics. Aims 2 and 3 will explore features of related compound families that, based on our hypotheses, are expected to facilitate more potent inhibition of bacterial ribosomes while maintaining selectivity/safety and enhancing broad spectrum antibacterial activity.

项目摘要 该项目的长期目标是开发一类新的广谱抗生素，重点是 革兰氏阴性细菌和结核病。此外，拟议的项目将教导如何优化抑制剂 仅在细菌中定义临界相互作用来定义核核核糖体的核糖体。受自然的启发 产品，该类靶向细菌核糖体的意外结合位点。随着报告的报告 对前线抗菌疗法的抵抗力，对新代理有至关重要的需求，但几乎没有发现 在开发管道中。结果，任何针对革兰氏阴性细菌和/或的新理论 结核病将满足未满足的医疗需求。 一种可行的方法来发现新的治疗铅是重新评估现有的但不足的班级 天然产品。通过这种方法，天然产品脚手架被确定为程序的领导 针对结核病的抗生素。对其他细菌的活动的初步评估表明 抗菌光谱仅限于分枝杆菌。但是，基于化学结构和 相关化合物，我们希望能够产生具有更广泛活性的类似物。 与汤姆·斯蒂茨（Tom Steitz 核糖体最近解决了。结构研究表明，天然产物的铅和类似物 与肽基转移酶中心（PTC）高度组成的区域结合，以似乎传达的方式 原核选择性，并且在当前疗法中尚未探索。高度针对这个 保守区域有望导致阻力速度缓慢。 这些结构信息用于产生两个具有良好理化学的潜在类似物 特性。在一个非常初步的SAR运动中，大约30种化合物，我们重新设计了一部分铅 合成简单性和稳定性的脚手架，提供两个类似物，这些类似物将MTB以外的活动引入到 MRSA，大肠杆菌和K.肺炎（包括碳青霉菌菌株），并且不表现出细胞毒性 真核细胞（IC50> 100 µm）。 该项目将探索并进一步定义抑制剂与细菌核糖体的关键结合相互作用 抑制细菌蛋白合成和广谱抗菌活性的选择性赋予选择性 保持缺乏哺乳动物的细胞毒性。 AIM 1将阐述我们关于复合如何如何的假设 选择性地结合未策划的位点的原核核糖体。如果我们的假设正确，这些抑制剂将 对哺乳动物核糖体不活跃，从而减轻其他核糖体靶向的限制 抗生素。 AIM 2和3将探索相关复合家庭的特征，基于我们的假设是 预计将促进对细菌核糖体的潜在抑制，同时保持选择性/安全性和 增强广谱抗菌活性。