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: 7884373
• 负责人: FOCCO VAN DEN AKKER
• 金额: $ 26.26万
• 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 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7884373
• 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（由申请人提供）：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有细菌感染，这通常是致命的组合。由于抗药性的发展，治疗感染的选择大大减少了。这种耐药性在很大程度上是由于β-内酰胺酶的细菌表达降低了β-内酰胺抗生素，包括青霉素，头孢菌素和“最后的度假胜地”碳青霉烯抗生素。一种治疗P-内酰胺抗性革兰氏阴性感染的替代方法是除了青霉素样抗生素外，还可以辅助使用P-内酰胺酶抑制剂。遗憾的是，P-内乳酶也发展了一种抗抑制剂的表型，能够克服这种治疗选择。水解这些抑制剂的P-内酰胺酶变体称为抑制剂耐药[3-乳糖苷酶，水解头孢菌素的抑制剂被称为延长的折光P-内酰胺酶（ESBLS），而水解碳二苯甲酸酶的P型谱酶被称为carbapenemase。该提案的总体目标是了解ESBL-，碳二烯酶和抑制剂耐药的P-内酰胺酶的表型的结构基础，并制定新颖的抑制策略。我们的结构功能研究涉及X射线和拉曼晶体学之间的新型协同作用，而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内部的中间体，并为实现我们的目标提供了独特的优势。 AIM 1：为了进一步改善我们新型设计的β-内酰胺酶抑制剂SA2-13，通过修改整体电荷和羧基接头以改善摄取和反式 - 内胺稳定。 AIM 2：测试以下假设：ESBL的SHV -6，-8和-24中存在的D179的变化或接近D179的变化已通过移动欧米茄环路而演变为水解头孢兹吉时，从而扩展了活性位点以容纳Ceftazidime。目标3：测试假设A类碳青霉酶（例如KPC-2）采用了较浅的活性位点和柔性催化870侧链来有效地水解碳青霉烯。目的4：要测试可以进行双囊化（例如LN1-255）或FRA/IS-内氨基抑制剂（SA2-13）的抑制剂（例如LN1-255）的抑制剂（SA2-13），能够与抗抑制剂A类A类和抑制剂抑制剂抑制剂抑制剂和抑制剂抑制剂抑制剂和抑制剂抑制剂抑制剂。 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，损失了数十亿美元的医疗保健费用。需要详细的理解，我们有针对性的结构知识将提供分子见解，例如最近在纽约举行的KPC KPC介导的耐碳青霉烯氏菌K.肺炎的爆发。这些抗性见解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。