Transport across two membranes by AcrAB-TolC

AcrAB-TolC 跨两膜转运

• 批准号: 9885979
• 负责人: HELEN I ZGURSKAYA
• 金额: $ 54.87万
• 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/9885979
• 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; combat; design; drug discovery; efflux pump; experimental study; inhibitor/antagonist; 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 大肠杆菌的Acrab-tolc示例的多物外排泵是临床的主要贡献者 在发病机理和慢性感染过程中，细菌和各种适应性反应的抗生素耐药性。 在上一个资金期间，我们在两个领域取得了重大进展：1）了解分子 外排泵组件的机理和周质膜融合蛋白在多药于外排的作用 跨两个膜； 2）开发一种协同计算和经验方法 通过新颖的作用机理发现外排泵抑制剂。我们成功地将这些进步应用于 通过与ACRA相互作用并抑制Acrab-的组装来发现以新颖方式起作用的抑制剂 TOLC复合物。这些外排泵抑制剂增强了多种细菌中多种抗生素的活性。这 拟议研究的主要目标是建立新外排泵抑制剂的分子机制 并优化这些抑制剂，以与特定的抗生素结合使用和针对特定的多药 抗性细菌。潜在的假设是发现的抑制剂的广泛增强活性是 由其独特的机制引起的，该机制将外排泵置于组装不力和漏水的构象中。在 提出的方法，生化，结构和动力学实验将与先进的 计算以表征外排泵抑制剂的机制，并优化作用于外排的抑制剂 抗多药抗杆菌的泵。为了优化抑制剂，我们将应用于我们的 知识最全面的平台可用。该平台利用一组带有可变流出的应变 能力和外膜渗透性障碍，并允许建立结构活动关系 分别以避免外膜，抑制和渗透到外膜。成功完成 提出的实验将有助于设计外排泵抑制剂，即使在 抗生素耐药性的多个泵和机制。