Mechanistic studies and inhibition strategies for antibiotic resistance

抗生素耐药性的机制研究和抑制策略

• 批准号: 7658125
• 负责人: FOCCO VAN DEN AKKER
• 金额: $ 26.52万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-15 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7658125
• 关键词: Active Sites; Adopted; Affect; Amides; Amines; Antibiotic Resistance; Antibiotics; Bacterial Infections; Binding; Carbapenems; Ceftazidime; Cephalosporins; Charge; Complex; Crystallography; Cyclization; Disease Outbreaks; Entropy; Goals; Health; Health Care Costs; Human; Hydrolysis; Infection; Klebsiella pneumonia bacterium; Knowledge; Lactamase; Lactams; Lead; Length; Mediating; Molecular; Monobactams; New York; Penicillins; Phenotype; Point Mutation; Reaction; Research Personnel; Resistance; Resistance development; Resort; Roentgen Rays; Side; Structure; Tazobactam; Testing; Variant; Virus Diseases; analog; base; beta-Lactamase; beta-lactamase PSE-2; carbapenemase; cost; deacylation; design; flexibility; flu; improved; inhibitor/antagonist; innovation; insight; methyl group; mutant; novel; novel therapeutic intervention; programs; pyridine; unsaturated bonds; uptake

DESCRIPTION (provided by applicant): Bacterial infections pose serious threats to human health. Furthermore, viral infections such as the flu are frequently accompanied by bacterial infections which is often a deadly combination. Due to the development of resistance, the options for treating infections have dwindled substantially. This resistance is in large part due to the bacterial expression of beta-lactamases that degrade beta-lactam antibiotics including penicillins, cephalosporins, and the "last resort" carbapenem antibiotics. An alternative approach for treating p-lactam resistant gram-negative infections is co-administering a p-lactamase inhibitor in addition to penicillin-like antibiotics. Regrettably, p-lactamases have also evolved an inhibitor-resistant phenotype able to overcome this treatment option. The p-lactamase variants that hydrolyze these inhibitors are called inhibitor resistant [3-lactamases, those that hydrolyze cephalosporins are called extended-spectrum p-lactamases (ESBLs), and those that hydrolyze carbapenems are known as carbapenemases. The overarching goals of this proposal are to understand the structural basis of the phenotypes of ESBL-, carbapenemase-, and inhibitor resistant p-lactamases, and to develop novel inhibition strategies. Our structure-function studies involve a novel synergy between X-ray and Raman crystallography and this innovative inter-disciplinary approach allows us to identify and track reaction intermediates inside crystals prior to X-ray analysis and provides a unique advantage to accomplish our Aims. Aim 1: To further improve our novel designed beta-lactamase inhibitor SA2-13 by modifying the overall charge and carboxyl linker to improve uptake and trans-enamine stabilization. Aim 2: To test the hypothesis that the changes in or near D179 which are present in ESBL's SHV-6, -8, and -24 have evolved to hydrolyze ceftazidime by shifting the omega loop thereby extending the active site to accommodate ceftazidime. Aim 3: To test the hypothesis that class A carbapenemases such as KPC-2 have adopted a shallower active site and flexible catalytic 870 side chain to efficiently hydrolyze carbapenems. Aim 4: To test the hypothesis that inhibitors that either can carry out bi-cyclization (such as LN1-255) or fra/is-enamine inhibitors (SA2-13) are capable of forming stable inhibitory complexes with inhibitor-resistant class A and inhibitor-insensitive class D p-lactamases. The impact of beta-lactamase mediated antibiotic resistance on human health is enormous, costing billions of dollars in health care costs. Detailed understanding is needed and our targeted structural knowledge will provide for molecular insights into cases such as the recent outbreaks of KPC mediated carbapenem-resistant K. pneumoniae in New York. These resistance insights will lead to new therapeutic approaches and our goal is to study and develop new broad-spectrum beta-lactamase inhibitors.

描述(申请人提供)：细菌感染对人类健康构成严重威胁。此外，流感等病毒感染经常伴随细菌感染，而细菌感染往往是致命的组合。由于耐药性的发展，治疗感染的选择大幅减少。这种耐药性在很大程度上是由于细菌表达的β-内酰胺酶能降解包括青霉素、头孢菌素和碳青霉烯类抗生素在内的β-内酰胺类抗生素。治疗耐β-内酰胺类革兰氏阴性感染的另一种方法是在青霉素类抗生素的基础上联合使用β-内酰胺酶抑制剂。遗憾的是，β-内酰胺酶也进化出一种耐药表型，能够克服这种治疗选择。降解这些抑制剂的β-内酰胺酶变种称为耐药[3-内酰胺酶]，那些降解头孢菌素的称为超广谱β-内酰胺酶(ESBLS)，而那些水解碳青霉烯类抗生素的称为碳青霉烯酶。这项建议的主要目标是了解耐ESBL、碳青霉烯酶和抑制剂的β-内酰胺酶表型的结构基础，并开发新的抑制策略。我们的结构-功能研究涉及X射线和拉曼结晶学之间的一种新的协同作用，这种创新的跨学科方法使我们能够在X射线分析之前识别和跟踪晶体中的反应中间体，并为实现我们的目标提供独特的优势。目的1：进一步改进我们设计的新型β-内酰胺酶抑制剂SA2-13，通过修饰总电荷和羧基连接物来提高摄取和反式-烯胺的稳定性。目的2：验证ESBL的SHV-6、-8和-24的D179位或附近的变化是否通过改变omega环从而扩展活性部位以适应头孢他啶而进化为水解头孢他啶的假说。目的：验证KPC-2等A类碳青霉烯酶采用较浅的活性中心和灵活的催化870侧链高效水解碳青霉烯类抗生素的假说。目的：验证可以进行双环化反应的抑制剂(如LN1-255)或fra/is-enamine抑制剂(SA2-13)能够与耐药的A类和不敏感的D类β-内酰胺酶形成稳定的抑制复合体的假说。β-内酰胺酶介导的抗生素耐药性对人类健康的影响是巨大的，花费了数十亿美元的医疗费用。我们需要详细的了解，我们有针对性的结构知识将为诸如最近纽约爆发的KPC介导的碳青霉烯耐药肺炎克雷伯菌等病例提供分子洞察力。这些耐药洞察力将导致新的治疗方法，我们的目标是研究和开发新的广谱β-内酰胺酶抑制剂。