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.

项目概要 项目 2：靶向革兰氏阳性细胞包膜组装 侵袭性耐甲氧西林金黄色葡萄球菌 (MRSA) 和耐药肺炎链球菌 在美国，抗生素耐药性感染导致的所有死亡中近 50% 是由这些感染造成的 国家。保守估计，每年有 900,000 例感染病例，这意味着它们 在可预见的未来仍将是一种威胁。识别这些生物体中的新漏洞至关重要 并维持可用于治疗其引起的感染的靶标和化合物的管道。在这个 根据提案，我们将追求金黄色葡萄球菌和肺炎链球菌的细胞包膜目标，强调那些 对于屏障完整性至关重要，因为针对它们可以允许继续使用抗生素 生物体已经产生了广泛的耐药性，例如β-内酰胺。目标 1 将采用复合驱动 金黄色葡萄球菌新靶点发现方法，利用结合途径的创新平台- 使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 将采用目标驱动的方法来加深我们对 LtaS 的机制和结构，LtaS 是一种在革兰氏菌上合成脂磷壁酸的多胞膜蛋白。 细胞表面呈阳性。根据工具化合物的发现，我们还将鉴定金黄色葡萄球菌 LtaS 使用路径导向筛选方法的抑制剂。目标3将重点关注磷壁酸的监管 肺炎链球菌中的聚合物。脂磷壁酸和壁磷壁酸（WTA）之间的平衡 已发现该病原体的表面可在空间上控制细胞壁水解酶以引导 PG 的扩展 生长过程中的网状结构。为了防止溶菌，必须仔细控制肺炎链球菌（一种 β-内酰胺利用了脆弱性，从而促进了墙中 WTA 含量的急剧增加。我们 已鉴定出一种必需的 WTA 水解酶 (WhyD)，当其失活时，可模拟 β-内酰胺治疗 增加 WTA 水平并诱导细胞裂解。我们将描述这种酶的功能和调节 研究其作为新型自溶诱导治疗靶点的潜力。