Targeting bacterial cell division with small molecules and peptides

用小分子和肽靶向细菌细胞分裂

• 批准号: 10510080
• 负责人: WILLIAM MARGOLIN
• 金额: $ 23.4万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10510080
• 关键词: Address; Adjuvant; Affect; Affinity; Animal Model; Anti-Bacterial Agents; Antibiotics; Architecture; Bacillus subtilis; Bacteria; Bacterial Antibiotic Resistance; Bacterial Drug Resistance; Bacteriophages; Benzamides; Binding; Binding Sites; Cell division; Cell membrane; Cells; Complement; Cytology; Data; Disabled Persons; Ensure; Enzymes; Escherichia coli; Fluorescence Microscopy; Foundations; Future; Genetic; Gram-Negative Bacteria; Gram-Positive Bacteria; Guanosine Triphosphate Phosphohydrolases; Health; Homologous Gene; Human; Impairment; In Vitro; Kinetics; Laboratories; Lead; Learning; Light; Lytic Phase; Mammalian Cell; Membrane; Methods; Microscopy; Modeling; Molecular; Molecular Mechanisms of Action; Monobactams; Nuclear Magnetic Resonance; Peptides; Peptidoglycan; Peptidyltransferase; Pharmaceutical Chemistry; Pharmaceutical Preparations; Physiological; Polymers; Proliferating; Proteins; Reporting; Resistance; Site; Surface Plasmon Resonance; Testing; Therapeutic; Toxic effect; Tubulin; Work; antimicrobial; base; cell envelope; cell killing; crosslink; daughter cell; design; druggable target; efflux pump; experimental study; in vivo; inhibitor; insight; methicillin resistant Staphylococcus aureus; mutant; novel; pathogen; pathogenic bacteria; polymerization; protein complex; recruit; small molecule; small molecule inhibitor; structural biology; synergism; targeted treatment; z-ring

Resistance to antibacterial therapies continues to be an urgent threat to human health, particularly bacteria that are already resistant to multiple antibiotics. To discover and develop new antibacterials, it is important to find and exploit under-utilized antibiotic targets. One attractive candidate is the divisome, the dynamic protein complex that splits bacterial cells in two. The bacterial divisome contains a set of highly conserved and essential proteins that act coordinately to ensure the correct timing and placement of the cell division septum at mid-cell. The septal transpeptidase is already a target of several widely used beta-lactam antibiotics, but no other divisome protein is currently targeted. FtsZ, a highly conserved polymer-forming GTPase that forms a membrane-associated "Z ring" required for organizing the septal transpeptidase and other septum-synthesizing enzymes, is the only other divisome protein that has been studied extensively as a target of small molecules and peptides, and our lab has helped to advance the understanding of FtsZ and its interacting proteins for 30 years. Nevertheless, there is still much to learn about how small molecules perturb FtsZ function at the molecular and cellular level and whether these can lead to potential therapeutics. To address this over-arching theme, this proposal seeks to define, structurally and physiologically, two different sets of promising new small molecule inhibitors of FtsZ. The first is a set of two related benzamide derivatives, synthesized by our medicinal chemistry collaborators, that have high potencies against both Gram-positive bacteria and Gramnegative bacteria with disabled efflux pumps. These derivatives were synthesized to have optimized binding to the interdomain cleft (IDC) of FtsZ, a common target of inhibitors that we have termed FtsZ's "Achilles Heel". Unexpectedly, we found that these two compounds perturb FtsZ by distinct mechanisms in Gram-positive versus Gram-negative bacteria, prompting the hypothesis that they disrupt FtsZ's ability to assemble into the proper condensed polymer architecture needed for cell division to progress further. This model will be tested with our laboratory's unique interdisciplinary array of genetic, cytological, and structural biology methods. The second set of small molecule inhibitors is a pair of bacteriophage peptides that have evolved to target FtsZ as part of their lytic cycle. Each peptide binds directly to FtsZ and blocks Z ring assembly, but also binds to another essential divisome protein that tethers FtsZ to the cytoplasmic membrane. The molecular details of these binding sites are unknown, but we hypothesize that they do not involve the FtsZ IDC and instead perturb Z ring assembly by novel two-pronged mechanisms. Again, we will apply our extensive expertise in genetics, microscopy and structural biology of divisome proteins to elucidate these mechanisms. The insights we will gain from the proposed studies should lay a foundation for the future therapeutic potential of small molecules and peptides, potentially in combination with each other or with other antibiotics, to kill bacteria by disrupting the cell division machinery.

对抗菌治疗的耐药性仍然是对人类健康的紧迫威胁，特别是细菌 已经对多种抗生素产生抗药性的细菌为了发现和开发新的抗菌药物，重要的是 寻找并利用未被充分利用的抗生素靶点。一个有吸引力的候选者是分裂体，动态蛋白质 将细菌细胞一分为二的复合体。细菌分裂体含有一组高度保守的， 协调作用以确保细胞分裂隔膜的正确时间和位置的必需蛋白质。 中间细胞中隔转肽酶已经是几种广泛使用的β-内酰胺类抗生素的靶点，但没有 目前靶向的是其它分裂体蛋白。FtsZ，一种高度保守的聚合物形成GTdR， 膜相关的“Z环”需要组织隔转肽酶和其他隔合成 酶，是唯一的其他分裂蛋白，已被广泛研究的小分子的目标 和肽，我们的实验室已经帮助推进了对FtsZ及其相互作用蛋白质的理解， 年尽管如此，关于小分子如何干扰FtsZ在细胞内的功能，还有很多东西需要了解。 分子和细胞水平，以及这些是否可以导致潜在的治疗。为了解决这一过度 主题，这项建议旨在定义，结构和生理，两套不同的有前途的新的小 FtsZ的分子抑制剂。第一个是一组两个相关的苯甲酰胺衍生物，由我们的合成。 药物化学合作者，对革兰氏阳性菌和革兰氏阴性菌都具有高效力 外排泵失效的细菌。合成这些衍生物以优化与 FtsZ的结构域间裂缝（IDC），我们称之为FtsZ的“阿喀琉斯之踵”的抑制剂的共同目标。 出乎意料的是，我们发现这两种化合物在革兰氏阳性细胞中通过不同的机制干扰FtsZ。 与革兰氏阴性细菌相比，提示假设它们破坏了FtsZ组装成 细胞分裂进一步进行所需的适当的缩合聚合物结构。这个模型将被测试 我们实验室独特的遗传学、细胞学和结构生物学方法的跨学科阵列。的 第二组小分子抑制剂是一对噬菌体肽，其已经进化为靶向FtsZ， 是它们裂解周期的一部分每种肽直接结合FtsZ并阻断Z环组装，但也结合FtsZ。 另一种将FtsZ束缚在细胞质膜上的必需分裂体蛋白。分子细节 这些结合位点是未知的，但我们假设它们不涉及FtsZ IDC，而是干扰FtsZ IDC。 Z形环装配采用新颖的两叉机构。同样，我们将运用我们在遗传学方面的广泛专业知识， 分裂蛋白的显微镜和结构生物学来阐明这些机制。我们的洞察力 这些研究成果将为小分子药物未来的治疗潜力奠定基础 和肽，潜在地彼此组合或与其他抗生素组合，通过破坏 细胞分裂机制