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.

抗微生物剂耐药性的迅速出现对细菌感染的治疗提出了重大挑战。碳青霉烯类耐药肠杆菌科（CRE）、鲍曼不动杆菌和铜绿假单胞菌尤其值得关注。我们显然需要几种新的革兰氏阴性菌制剂，这些制剂在负债和抗菌剂类别方面是独特的，可以使我们的抗菌剂开发组合多样化。该多PI提案研究了称为链丝菌素的天然产物，其含有三个部分：链甲苯胺、古洛糖胺糖和不同长度的单个β-赖氨酸或聚β-赖氨酸链。70多年前发现了链丝菌素，并通过广泛的蛋白质错误编码抑制蛋白质翻译。在初步实验中，我们确定链丝菌素（天然产物混合物也称为诺尔丝菌素）对多重耐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-赖氨酸部分的链丝菌素-F，我们在体外和体内鉴定了令人信服的活性。然而，在革兰氏阴性病原体中低频率发现的几种链丝菌素乙酰转移酶通过β-赖氨酸残基的β-胺的乙酰化赋予链丝菌素抗性。这些观察结果导致我们假设抗菌活性可以与毒性分离，同时通过β-赖氨酸部分和其他成分的衍生化/置换阻断这些抗生素耐药元件。因此，本提案的目标是使用链丝菌素类似物的有效的、多样性导向的药物化学合成来进行假设驱动的结构-活性关系研究，以优化该支架的治疗性质。特别是，我们建议功能配置文件每个链丝菌素类似物，以确定对有问题的革兰氏阴性病原体的效力，原核核糖体的选择性，毒性和代谢稳定性。将在小鼠模型中测试优先类似物的毒性、药物清除率和治疗功效。此外，优先类似物将在基于冷冻电镜的结构和自动对接研究中进行研究，以了解这些分子变体如何与A.鲍氏70 S核糖体。从这些研究中获得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。总之，该提案的目的中的实验将解决链丝菌素文献中缺乏系统探索的问题，并确定适合生产性修饰的分子成分，以增强该支架作为未来治疗剂的性能。