Structure of Proteins in Cell Walls by REDOR NMR

通过 REDOR NMR 分析细胞壁中的蛋白质结构

• 批准号: 6929074
• 负责人: JACOB SCHAEFER
• 金额: $ 22.33万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6929074
• 关键词: Structure; Proteins; Cell; Walls; REDOR

EXCEED THE SPACE PROVIDED. Vancomycin kills Gram-positive enterococci and staphylococci by interfering with cell-wall biosynthesis. We have shown that in wild-type Staphylococcus aureus, vancomycin binds to the stem termini of cell-wall precursors and inhibits transglycosylation (glycan chain extension). Recently, vancomycin-resistant enterococci and staphylococci have emerged. These bacteria have altered peptidoglycan structures and reduced vancomycin binding. We have used solid-state NMR to characterize the cell-wall complexes of five fluorinated glycopeptides with improved potency against vancomycin-resistant enterococci. We obtained two of the drugs from Eli Lilly Company, two from the Cause Institute of New Antibiotics (Russia), and one we synthesized ourselves. We have correlated structure and activity for these drugs for the first time and have formulated their mode of action. In the next grant period, we plan to prove or disprove the general hypothesis that these drugs kill vancomycin-resistant enterococci and staphylococci by interfering with template recognition during peptidoglycan biosynthesis. We believe that new peptidoglycan strands must be pre-ordered to fit into a tightly cross-linked three-dimensional network, and that this is the reason that an existing nearest-neighbor strand is used as a template for the synthesis of a new strand. We will test these notions using solid-state NMR detection of drug-complex formationand biosynthesis in whole cells of a variety of vancomycin-susceptible and vancomycin-resistant enterococci and staphylococci, organisms which we have acquired from our colleague- collaborators, P. Courvalin (France) and H. Labischinski (Germany). We will use highly selective stable-isotope labeling protocols with detection by new, specially designed solid-state NMR experiments. None of the glycopeptides with improved potency against vancomycin-resistant enterococci and staphylococci that we have examined are approved for clinical use in the United States because of deleterious side effects. We are hopeful that the insights into the mode(s) of action of these glycopeptides that will result from the work proposed in this applicationwill stimulate the search for new and potent antibiotics with tolerable side effects. PERFORMANCE SITE ========================================Section End===========================================

超出所提供的空间。万古霉素通过干扰细胞壁生物合成杀死革兰氏阳性肠球菌和葡萄球菌。我们已经证明，在野生型金黄色葡萄球菌中，万古霉素与细胞壁前体的茎末端结合并抑制转糖基化（聚糖链延伸）。近年来，出现了耐万古霉素的肠球菌和葡萄球菌。这些细菌具有改变的肽聚糖结构和减少的万古霉素结合。我们已经使用固态核磁共振来表征五个氟化糖肽的细胞壁复合物，其对万古霉素耐药肠球菌的效力有所提高。我们从礼来公司获得了两种药物，两种来自新抗生素事业研究所（俄罗斯），一种是我们自己合成的。我们首次将这些药物的结构和活性联系起来，并制定了它们的作用模式。在下一个资助期，我们计划证明或反驳这些药物通过干扰肽聚糖生物合成过程中的模板识别来杀死万古霉素耐药肠球菌和葡萄球菌的一般假设。我们认为，新的肽聚糖链必须预先排序，以适应一个紧密交联的三维网络，这就是为什么现有的最近邻链被用作合成新链的模板。我们将使用固态NMR检测药物复合物的形成和在各种万古霉素敏感和耐万古霉素肠球菌和葡萄球菌的全细胞中的生物合成来测试这些概念，这些生物体是我们从我们的同事-合作者P. Courvalin（法国）和H. Labischinski（德国）.我们将使用高选择性的稳定同位素标记协议与检测新的，专门设计的固态核磁共振实验。我们所研究的对万古霉素耐药肠球菌和葡萄球菌具有更高效力的糖肽类药物，由于其有害的副作用，在美国没有一种被批准用于临床。我们希望，从本申请中提出的工作中获得的对这些糖肽作用模式的见解将刺激寻找具有可耐受副作用的新的有效抗生素。性能现场=