Project 2: Targeting Gram-positive Cell Envelope Assembly

项目 2：靶向革兰氏阳性细胞包膜组装

• 批准号: 10699955
• 负责人: Suzanne Walker
• 金额: $ 73.23万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-07 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10699955
• 关键词: Anabolism; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotics; Antimicrobial Cationic Peptides; Autolysis; Bacteriolysis; Binding; Biochemical; Biochemistry; Biogenesis; Biological Assay; Biology; Categories; Cell Wall; Cell division; Cell surface; Cells; Cessation of life; Chemicals; Cytolysis; Defect; Development; Diglycerides; Drug resistance; Enzymes; Equilibrium; Future; Gene Deletion; Genetic; Genomics; Gram-Positive Bacteria; Growth; Hydrolase; Infection; Membrane; Membrane Proteins; Methods; Organism; Pathogenesis; Pathway interactions; Physiology; Play; Pneumococcal Infections; Polymers; Predisposition; Prevalence; Process; Protein Biosynthesis; Reaction; Recycling; Regulation; Resistance; Role; Staphylococcus aureus; Staphylococcus aureus infection; Streptococcus pneumoniae; Structure; Surface; Teichoic Acids; Translations; Transmembrane Domain; United States; Virulence; Work; antibiotic resistant infections; bacterial genetics; beta-Lactam Resistance; beta-Lactams; cell envelope; cell growth; experience; inhibitor; innovation; lipoteichoic acid; member; methicillin resistant Staphylococcus aureus; multidisciplinary; mutant; novel; pathogen; prevent; reconstitution; response; screening; small molecule inhibitor; structural biology; therapeutic development; therapeutic target; tool; transposon sequencing

PROJECT SUMMARY Project 2: Targeting Gram-positive Cell Envelope Assembly Invasive methicillin-resistant Staphylococcus aureus (MRSA) and drug-resistant Streptococcus pneumoniae infections together are responsible for almost 50% of all deaths due to antibiotic-resistant infections in the United States. Their prevalence, conservatively estimated at a combined 900,000 infections each year, means that they will continue to be a threat for the foreseeable future. It is crucial to identify new vulnerabilities in these organisms and to maintain a pipeline of targets and compounds that can be used to treat the infections they cause. In this proposal, we will pursue cell envelope targets in S. aureus and S. pneumoniae, emphasizing those that are critical for barrier integrity because targeting them could allow continued use of antibiotics to which these organisms have developed widespread resistance, such as beta-lactams. Aim 1 will take a compound-driven approach to new target discovery in S. aureus that exploits an innovative platform that combines pathway- directed chemical screening with a transposon-based pipeline to rapidly identify targets for compounds that inhibit cell envelope processes. Aim 2 will take a target-driven approach that advances our understanding of the mechanism and structure of LtaS, a polytopic membrane protein that synthesizes lipoteichoic acids on the Gram- positive cell surface. Based on discoveries made with a tool compound, we will also identify S. aureus LtaS inhibitors using a pathway-directed screening approach. Aim 3 will focus on the regulation of teichoic acid polymers in S. pneumoniae. The balance between lipoteichoic acids and wall teichoic acids (WTAs) on the surface of this pathogen have been found to spatially control cell wall hydrolases to guide expansion of the PG meshwork during growth. To prevent bacteriolysis, WTA levels must be carefully controlled in S. pneumoniae, a vulnerability exploited by beta-lactams, which promote a dramatic increase in the WTA content of the wall. We have identified an essential WTA hydrolase (WhyD) that when inactivated mimics beta-lactam treatment to increase WTA levels and induce cell lysis. We will characterize the function and regulation of this enzyme and investigate its potential as a novel autolysis-inducing therapeutic target.

项目总结 项目2：靶向革兰氏阳性细胞包膜组件 侵袭性耐甲氧西林金黄色葡萄球菌和耐药肺炎链球菌 在美国，耐药感染导致的死亡人数几乎占所有死亡人数的50%。 各州。保守估计，他们的流行率每年总共有90万人感染，这意味着他们 在可预见的未来仍将是一个威胁。识别这些生物中的新脆弱性是至关重要的。 并维持一系列靶点和化合物，可用于治疗它们引起的感染。在这 提议，我们将在金黄色葡萄球菌和肺炎链球菌中寻找细胞包膜靶点，重点是那些 对于屏障的完整性至关重要，因为靶向它们可能允许继续使用抗生素，这些 生物体已经产生了广泛的耐药性，如β-内酰胺类药物。目标1将采用复合驱动的 利用结合途径的创新平台在金黄色葡萄球菌中发现新目标的方法- 利用基于转座子的管道进行定向化学筛选，以快速识别化合物的靶标 抑制细胞包膜过程。目标2将采取目标驱动的方法，促进我们对 Ltas是一种在革兰氏细胞表面合成脂磷壁酸的多聚体膜蛋白，其作用机制和结构与功能有关。 阳性细胞表面。根据工具化合物的发现，我们还将鉴定金黄色葡萄球菌。 使用途径导向筛选方法的抑制剂。目标3将重点放在磷壁酸的调节上 肺炎链球菌中的聚合物。脂磷壁酸与壁磷壁酸之间的平衡 已经发现这种病原体的表面可以空间控制细胞壁水解酶来引导PG的扩张 生长过程中的网络。为了防止细菌溶解，必须仔细控制肺炎链球菌的WTA水平。 被β-内酰胺类药物利用的脆弱性，这促进了墙中WTA含量的急剧增加。我们 已经确定了一种必要的WTA水解酶(Whyd)，当灭活时，它模仿β-内酰胺处理来 提高WTA水平，诱导细胞裂解。我们将对这种酶的功能和调节进行表征，并 研究其作为一种新的自溶诱导治疗靶点的潜力。