Transport across two membranes by AcrAB-TolC

AcrAB-TolC 跨两膜转运

• 批准号: 10377970
• 负责人: HELEN I ZGURSKAYA
• 金额: $ 49.39万
• 依托单位: UNIVERSITY OF OKLAHOMA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10377970
• 关键词: Acinetobacter baumannii; Address; Affect; Antibiotic Resistance; Antibiotics; Area; Bacteria; Bacterial Infections; Biochemical; Cell Membrane Permeability; Chemosensitization; Chimeric Proteins; Clinical; Colistin; Complex; Development; Escherichia coli; Funding; Goals; Infection; Kinetics; Knowledge; Libraries; Membrane; Membrane Fusion; Molecular; Molecular Conformation; Multi-Drug Resistance; Multidrug-resistant Acinetobacter; Multiple Bacterial Drug Resistance; Pathogenesis; Permeability; Pharmaceutical Chemistry; Pharmaceutical Preparations; Proteins; Pump; Research; Resistance; Role; Series; Structure; Structure-Activity Relationship; Therapeutic; Toxic effect; Virulence; Walkers; antibiotic efflux; base; chronic infection; clinical application; clinical development; design; drug discovery; efflux pump; experimental study; inhibitor; insight; models and simulation; multidisciplinary; novel; periplasm; preclinical study; preservation; resistance mechanism; resistant strain; response; therapeutic target; tool

Project Description Multidrug efflux pumps as exemplified by AcrAB-TolC from Escherichia coli are the major contributors to clinical antibiotic resistance in bacteria and to various adaptive responses during pathogenesis and chronic infections. During the previous funding period, we made major advances in two areas: 1) understanding the molecular mechanism of efflux pump assembly and the role of periplasmic membrane fusion proteins in multidrug efflux across two membranes; and 2) the development of a synergistic computational and empirical approach to discovering efflux pump inhibitors with novel mechanisms of action. We successfully applied these advances to discover inhibitors that act in a novel way, by interacting with AcrA and inhibiting the assembly of the AcrAB- TolC complex. These efflux pump inhibitors potentiate activities of multiple antibiotics in various bacteria. The major goal of the proposed research is to establish the molecular mechanisms of the new efflux pump inhibitors and to optimize these inhibitors for use in combination with specific antibiotics and against specific multidrug resistant bacteria. The underlying hypothesis is that the broad potentiation activity of the discovered inhibitors is caused by their unique mechanism that traps efflux pumps in a poorly assembled and leaky conformation. In the proposed approach, biochemical, structural and kinetic experiments will be used synergistically with advanced computations to characterize the mechanism of efflux pump inhibitors and to optimize inhibitors acting on efflux pumps of multidrug resistant Acinetobacter baumannii. To optimize inhibitors, we will apply what is to our knowledge the most comprehensive platform available. The platform utilizes a set of strains with variable efflux capacities and outer membrane permeability barriers and allows to establish structure-activity relationships separately for efflux avoidance, inhibition and permeation across the outer membrane. Successful completion of the proposed experiments will help design efflux pump inhibitors that would be effective even in the context of multiple pumps and mechanisms of antibiotic resistance.

项目描述 以大肠杆菌 AcrAB-TolC 为例的多药外排泵是临床的主要贡献者 细菌的抗生素耐药性以及发病机制和慢性感染期间的各种适应性反应。 在上一个资助期间，我们在两个领域取得了重大进展：1）了解分子 外排泵组装机制和周质膜融合蛋白在多药外排中的作用 跨越两层膜； 2）开发协同计算和实证方法 发现具有新颖作用机制的外排泵抑制剂。我们成功地将这些进步应用于 发现了通过与 AcrA 相互作用并抑制 AcrAB 组装以新颖方式发挥作用的抑制剂 TolC 复合物。这些外排泵抑制剂增强了多种抗生素在各种细菌中的活性。这 该研究的主要目标是建立新型外排泵抑制剂的分子机制 并优化这些抑制剂以与特定抗生素联合使用并针对特定的多药 耐药细菌。基本假设是所发现的抑制剂的广泛增强活性是 这是由于其独特的机制将外排泵困在组装不良和泄漏的构象中。在 所提出的方法、生化、结构和动力学实验将与先进的协同使用 计算来表征外排泵抑制剂的机制并优化作用于外排的抑制剂 多重耐药鲍曼不动杆菌泵。为了优化抑制剂，我们将应用我们的抑制剂 知识最全面的平台。该平台利用一组具有可变流出量的菌株 能力和外膜渗透屏障，并允许建立结构-活性关系 分别用于避免外流、抑制和跨外膜渗透。顺利完成 所提出的实验将有助于设计外排泵抑制剂，即使在以下情况下也能有效 抗生素耐药性的多种泵和机制。