Mechanistic Studies of Gyrase/Topoisomerase IV-Targeted Antibacterials

旋转酶/拓扑异构酶 IV 靶向抗菌药物的机理研究

基本信息

批准号：
10667862
负责人：
NEIL OSHEROFF
金额：
$ 66.89万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-03-23 至 2027-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10667862
关键词：
Acinetobacter baumannii Active Sites Amino Acids Anti-Bacterial Agents Aspartic Acid Bacillus anthracis Bacterial Drug Resistance Binding Bypass Cell Death Cell Death Induction Cells Ciprofloxacin Clinical Complex DNA DNA Damage DNA Double Strand Break DNA Maintenance DNA Topoisomerase IV Double Effect Drug Interactions Drug resistance Drug usage Enzyme Inhibition Enzymes Escherichia coli Fluoroquinolones Francisella tularensis Genetic Materials Genome Goals Handedness Health Human In Vitro Incidence Ions Laboratories Libraries Ligation Mediating Metals Monitor Mutation Mycobacterium tuberculosis Neisseria gonorrhoeae Neurofibrillary Tangles New Agents Oral Pharmaceutical Preparations Phase III Clinical Trials Physiological Positioning Attribute Publishing Research Resistance Role Serine Single-Stranded DNA Site Staphylococcus aureus Structure Superhelical DNA System Topoisomerase II Topoisomerase Inhibitors Toxin Water World Health Organization antimicrobial bacterial resistance cellular targeting clinical efficacy drug action fluoroquinolone resistance in vitro activity in vivo member mutant novel pathogen resistance mechanism targeted agent

项目摘要

Fluoroquinolones, such as ciprofloxacin, are among the most efficacious and broad-spectrum oral antibacterials in clinical use. The World Health Organization lists them in their five “Highest Priority Critically Important Antimicrobials,” and these drugs are the most heavily prescribed antibacterials worldwide. The cellular targets of fluoroquinolones are the bacterial type II topoisomerases, gyrase and topoisomerase IV. These essential enzymes regulate DNA under- and overwinding and remove knots and tangles from the genome by generating transient double-stranded breaks in the genetic material. Fluoroquinolones act by increasing levels of double-stranded DNA breaks generated by gyrase and topoisomerase IV, which converts these enzymes into cellular toxins that fragment the genome. Although gyrase and topoisomerase IV are both physiological targets for fluoroquinolones, their relative importance to drug action appears to be species- and drug-dependent. There is a growing crisis in antibacterial resistance and fluoroquinolone resistance is becoming prevalent. This resistance is threatening the clinical efficacy of fluoroquinolones. Initial fluoroquinolone resistance is most often associated with specific mutations in gyrase and/or topoisomerase IV that occur at a serine residue (originally described as Ser83 in the GyrA subunit of Escherichia coli gyrase) and a glutamic/aspartic acid residue 4 amino acids downstream. Based on a published structure and functional studies from the Osheroff laboratory, these residues are proposed to anchor a water-metal ion bridge that serves as the primary conduit between fluoro- quinolones and gyrase/topoisomerase IV. The identification and characterization of novel agents that act against these well-validated enzyme targets and overcome fluoroquinolone resistance could have important health ramifications. Recently, two new classes of gyrase/topoisomerase IV-targeted agents have been described that appear to overcome this resistance, Novel Bacterial Topoisomerase Inhibitors (NBTIs) and Spiropyrimidinetriones (SPTs). Members of these classes, gepotidacin (NBTI) and zoliflodacin (SPT), have advanced to Phase 3 clinical trials. NBTIs are unique, as they induce single- rather than double-stranded enzyme-generated DNA breaks. However, little is known about the actions of NBTIs and SPTs against gyrase/topoisomerase IV or the mechanism of drug resistance. There is an urgent need to identify drugs that display activity against fluoroquinolone-resistant bacteria. Thus, the goals of this project are to further define the mechanism of action of fluoroquinolones, NBTIs, and SPTs against gyrase and topoisomerase IV in vivo and in cells, to characterize the basis of target-mediated drug resistance, and to identify novel compounds that overcome resistance. Research will benefit from the broad library of wild- type and drug-resistant gyrase/topoisomerase IV available in the Osheroff laboratory, which includes enzymes from Bacillus anthracis, E. coli, Staphylococcus aureus, Mycobacterium tuberculosis, Neisseria gonorrhoeae, Francisella tularensis, and Acinetobacter baumannii. These pathogens have substantial effects on human health.

氟喹诺酮类（例如环丙沙星）是最有效，最广泛的口服临床用途中的抗菌作用。世界卫生组织将它们列在其五个“最高优先级”中重要的抗菌剂”，这些药物是全球规定的抗菌药物。氟喹诺酮类酮的细胞靶标是II型细菌拓扑异构酶，回旋酶和拓扑异构酶IV。这些必需酶调节DNA下和越来越多的DNA，并从基因组中去除结和缠结通过在遗传物质中产生瞬态双链断裂。氟喹诺酮通过增加水平的作用 Gyrase和Topoisomerase IV产生的双链DNA断裂，将这些酶转化为细胞毒素碎片基因组。尽管回旋酶和拓扑异构酶IV都是物理目标对于氟喹诺酮类药物，它们对药物作用的相对重要性似乎是物种和药物依赖性的。抗菌抗性的危机日益严重，氟喹诺酮耐药性变得普遍。这耐药性威胁着氟喹诺酮的临床效率。最初的氟喹诺酮类电阻通常是与在连续居住区发生的回旋酶和/或拓扑异构酶IV中的特异性突变有关（最初是在大肠杆菌回旋酶的Gyra亚基中被描述为Ser83）和谷氨酸/天冬氨酸住宅4氨基酸下游。基于Osheroff实验室的公开结构和功能研究，这些提出了残留物来锚定一个水平离子桥，该桥是氟 - 喹诺酮类和回旋酶/拓扑异构酶IV。针对这些验证良好的酶靶标的新型药物的识别和表征克服氟喹诺酮耐药性可能会产生重要的健康后果。最近，两个新课程已经描述了回旋酶/拓扑异构酶IV靶向剂的含量，似乎克服了这种抗性，细菌拓扑异构酶抑制剂（NBTIS）和螺旋吡迪尼酮（SPTS）。这些课程的成员， Gepotidacin（NBTI）和Zoliflodacin（SPT）已晋升为第三阶段临床试验。 NBTI是独一无二的诱导单链酶产生的DNA断裂。但是，关于 NBTI和SPT对回旋酶/拓扑异构酶IV或耐药性机理的作用。迫切需要鉴定出对抗氟喹诺酮类细菌的活性的药物。那，该项目的目标是进一步定义氟喹诺酮，NBTI和SPT的作用机理在体内和细胞中的回旋酶和拓扑异构酶IV，以表征靶介导的耐药性的基础，并确定克服抗性的新型化合物。研究将受益于广泛的野生图书馆 Osheroff实验室可用的类型和耐药的回旋酶/拓扑异构酶IV，其中包括酶来自炭疽芽孢杆菌，大肠杆菌，金黄色葡萄球菌，结核分枝杆菌，淋病奈瑟氏菌， Francisella tularensis和Acinetobacter Baumannii。这些病原体对人类健康有重大影响。