Use of De Novo Synthesis Approaches and Structure-guided Design to Optimize Therapeutic Properties of Streptothricin Class Antimicrobials

使用从头合成方法和结构引导设计来优化链丝菌素类抗菌药物的治疗特性

• 批准号: 10686110
• 负责人: JAMES E KIRBY
• 金额: $ 76.68万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-23 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10686110
• 关键词: Acetylation; Acinetobacter baumannii; Amines; Aminoglycosides; Anti-Bacterial Agents; Antibiotic Resistance; Bacterial Infections; Binding; Binding Sites; Biological Assay; Creatinine; Cryoelectron Microscopy; Derivation procedure; Development; Docking; Drug Kinetics; Elements; Escherichia coli; Eukaryotic Cell; FBXW7 gene; Feedback; Frequencies; Future; Goals; Gram-Negative Bacteria; Histopathology; Immune; Immunity; In Vitro; Infection; Kidney; Laboratories; Length; Literature; Lysine; Maximum Tolerated Dose; Metabolic; Methyltransferase; Modeling; Modification; Molecular; Multi-Drug Resistance; Mus; Mutation Analysis; Natural Products; Nevada; Operon; Pharmaceutical Chemistry; Pharmaceutical Preparations; Productivity; Property; Protein Inhibition; Proteins; Pseudomonas aeruginosa; Resistance; Ribosomal RNA; Ribosomes; Site; Structure; Structure-Activity Relationship; Synthesis Chemistry; Testing; Therapeutic; Therapeutic Effect; Thigh structure; Time; Toxic effect; Toxicology; Transferase; Translations; Treatment Efficacy; Variant; Virulent; Work; analog; antimicrobial; bactericide; carbapenem-resistant Enterobacteriaceae; chemical synthesis; cytotoxicity; design; drug clearance; emerging antimicrobial resistance; experimental study; in vitro activity; in vivo; insight; mouse model; novel; novel therapeutics; pathogen; pre-clinical; scaffold; sugar; tissue culture; translation assay

The rapid emergence of antimicrobial resistance presents a significant challenge for treatment of bacterial infections. Carbapenem-resistant Enterobacteriaceae (CRE), Acinetobacter baumannii, and Pseudomonas aeruginosa are of particular concern. We are clearly in need of several new Gram-negative agents that are unique in terms of liabilities and antimicrobial class and which can diversify our antimicrobial development portfolio. This multi-PI proposal investigates natural products called streptothricins, which contain three moieties: streptolidine, a gulosamine sugar, and a single β-lysine or poly-β-lysine chain of varying length. Streptothricins were identified over 70 years ago and inhibit protein translation with extensive protein miscoding. In preliminary experiments, we determined that streptothricins (the natural product mixture is also called nourseothricin) are broadly active against multidrug-resistant Gram-negative pathogens. In particular, for streptothricin-F, which has a single β-lysine moiety, we identified compelling activity in vitro and in vivo. However, several streptothricin acetyl transferases, found in low frequency in Gram-negative pathogens, confer streptothricin resistance by acetylation of the β-amine of the β-lysine residue. These observations led to our hypothesis that antibacterial activity can be separated from toxicities and at the same time these antibiotic resistance elements blocked through derivatization/replacement of the β-lysine moiety and other constituents. Therefore, the goals of this proposal are to use an efficient, diversity- oriented, medicinal chemistry synthesis of streptothricin analogues to perform hypothesis-driven structure- activity relationship studies to optimize therapeutic properties of this scaffold. In particular, we propose to functionally profile each streptothricin analogue to determine potency against problematic Gram-negative pathogens, selectivity for prokaryotic ribosomes, toxicity, and metabolic stability. Prioritized analogues will be tested in a mouse model for toxicity, drug clearance, and therapeutic efficacy. Furthermore, prioritized analogues will be investigated in cryo-EM based-structural and auto-docking studies to understand how these molecular variants differentially bind to the A. baumannii 70S ribosome. Structural insights from these studies will be used to provide iterative feedback to optimize design of analogues during the course of the proposed work. Taken together, the experiments in the aims of the proposal will address the lack of systematic exploration in the streptothricin literature and identify molecular constituents that are amenable to productive modification to enhance properties of this scaffold as a future therapeutic.

抗菌耐药的快速出现给细菌感染的治疗带来了重大挑战。抗碳青霉烯型肠杆菌科（CRE），baumannii和铜绿假单胞菌尤其令人关注。显然，我们需要几种在负债和抗菌类别方面独特的新革兰氏阴性药物，它们可以使我们的抗菌发育组合多样化。该多PI提案研究了称为链氨木蛋白的天然产物，其中包含三个部分：链肽氨酸，墨糖苷糖和一个多长度长度的单个β-赖氨酸或多β-赖氨酸链。 70年前鉴定出链霉菌素，并抑制蛋白质翻译，并具有广泛的蛋白质错误编码。在初步实验中，我们确定链植血素（自然产物混合物也称为Nourseothricin）对耐多药革兰氏阴性病原体具有广泛的活性。特别是，对于具有单个β-赖氨酸部分的链霉菌素F，我们在体外和体内鉴定了引人注目的活性。然而，在革兰氏阴性病原体中发现的几种链霉素乙酰基转移，乙酰化β-赖氨酸保留的β-胺通过乙酰化抗抑制蛋白的抗性。这些观察结果导致了我们的假设，即抗菌活性可以与毒性分离，同时这些抗生素耐药性元件通过衍生化/替代β-赖氨酸部分和其他结构而阻塞。因此，该提案的目标是使用链霉菌类似物的有效，以多样性为导向的药物化学合成来执行假设驱动的结构活性关系研究来优化该支架的治疗特性。特别是，我们建议在功能上介绍每个链霉素类似物，以确定针对有问题的革兰氏阴性病原体，原核生物核糖体的选择性，毒性和代谢稳定性的效力。优先类似物将在小鼠模型中测试毒性，药物清除和治疗有效性。此外，将在基于冷冻EM的结构和自动船上研究中研究优先的类似物，以了解这些分子变体如何与鲍曼尼A. baumannii 70S核糖体有不同的结合。这些研究的结构见解将用于提供迭代反馈，以在拟议的工作过程中优化类似物的设计。综上所述，该提案目的的实验将解决链霉菌蛋白文献中缺乏系统的探索，并鉴定出适合产品修饰的分子构成，以增强该脚手架作为未来治疗的特性。