Targeting bacterial cell division with small molecules and peptides

用小分子和肽靶向细菌细胞分裂

基本信息

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
项目类别：
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

项目摘要

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.

对抗菌疗法的抵抗仍然是对人类健康的紧迫威胁，尤其是细菌已经对多种抗生素具有抗药性。要发现和开发新的抗菌药物，重要的是查找并利用未充分利用的抗生素靶标。一个有吸引力的候选人是分裂蛋白的分裂蛋白复合物将细菌细胞分为两个。细菌分裂体包含一组高度保守和协调起作用的必需蛋白质，以确保细胞分裂的正确时间和位置中间细胞。间隔肽酶已经是几种广泛使用的β-内酰胺抗生素的靶标，但没有目前，其他分裂蛋白是针对的。 FTSZ，一种高度保守的聚合物GTPase，形成A 膜相关的“ Z环”，组织间隔转肽酶和其他隔膜合成酶，是唯一已被广泛研究为小分子靶标的其他分裂体蛋白和肽，我们的实验室有助于提高对FTSZ及其相互作用蛋白的理解30 年。然而，关于小分子的扰动FTSZ在分子和细胞水平以及它们是否会导致潜在的治疗剂。解决这个额外的问题主题，该建议旨在在结构和生理上定义两套有希望的新小型 FTSZ的分子抑制剂。第一个是两个相关的苯甲酰衍生物，由我们合成药物化学合作者，对革兰氏阳性细菌和革兰氏阴性菌具有很高的能力带有残疾外排泵的细菌。这些衍生物合成以优化与 FTSZ的域间裂口（IDC），这是我们称为FTSZ的“阿喀琉斯高跟鞋”的抑制剂的常见靶标。出乎意料的是，我们发现这两种化合物通过革兰氏阳性的不同机制扰动ftsz 与革兰氏阴性细菌相对于革兰氏阴性细菌，促使假设它们破坏了FTSZ组装到该的能力细胞分裂需要进一步发展所需的适当冷凝的聚合物结构。该模型将进行测试我们实验室独特的遗传，细胞学和结构生物学方法的独特跨学科阵列。这第二组小分子抑制剂是一对噬菌体肽，它们已进化为靶向FTSZ 它们的裂解周期的一部分。每种肽直接与FTSZ结合并阻止Z环组件，但也与将FTSZ推向细胞质膜的另一种必不可少的分裂体蛋白。分子细节这些绑定位点未知，但我们假设它们不涉及FTSZ IDC，而是扰乱 Z环由新颖的两种支撑机制。同样，我们将应用我们广泛的遗传学专业知识，分裂蛋白的显微镜和结构生物学，以阐明这些机制。我们会的见解从拟议的研究中获得的收益应为小分子的未来治疗潜力奠定基础和肽，可能相互或与其他抗生素结合使用，以通过破坏杀死细菌细胞部机械。