Detailed mapping of drug binding and translocation sites in the AcrB pump protein

AcrB 泵蛋白中药物结合和易位位点的详细图谱

• 批准号: 9210599
• 负责人: RAJEEV MISRA
• 金额: $ 22.01万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-27 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9210599
• 关键词: Alleles; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotics; Binding; Biochemical; Biochemistry; Biological Assay; Cells; Collaborations; Complex; Computer Simulation; Coupled; Cysteine; Cytoplasm; Data; Defect; Drug Efflux; Drug Kinetics; Drug resistance; Drug-sensitive; E coli tolC protein; Escherichia coli; Escherichia coli Proteins; Family; Genetic; Human; Individual; Ion Channel; Kinetics; Knowledge; Label; Ligands; Lipoproteins; Literature; Maps; Membrane; Modeling; Molecular; Movement; Multi-Drug Resistance; Mutation; Nodule; Outcome; Pathway interactions; Pharmaceutical Preparations; Pharmacodynamics; Positioning Attribute; Proteins; Protons; Pump; Resistance; Role; Site; Specificity; Spectrum Analysis; Structural Models; Structure; Study models; Substrate Specificity; System; Time; Variant; Work; cellular targeting; combat; dosage; efflux pump; functional plasticity; global health; inhibitor/antagonist; insight; molecular dynamics; mutant; nitrocefin; novel; pathogen; periplasm; public health relevance; resistance mechanism; stem; three dimensional structure

 DESCRIPTION (provided by applicant): The alarming rate at which human bacterial pathogens are becoming multidrug resistant is a grave global health concern. While antibiotic-specific pharmacokinetic and pharmacodynamic knowledge is being used to administer correct dosage of antibiotics, prodigious efforts are being made to search for novel antibacterial compounds and cellular targets, and to gain a deeper understanding of the mechanism of drug resistance. One such mechanism involves the elevated expression of multidrug resistance efflux pumps to combat the drug influx across the bacterial envelope, thereby conferring resistance to a multitude of antibiotics. A major class of such drug efflux pumps, uniformly conserved in all Gram-negative human bacterial pathogens, belongs to the Resistance-Nodulation-Division (RND) family. A constitutively expressed RND pump complex of Escherichia coli comprises of AcrA, AcrB, and TolC proteins, which when assembled, bridge the inner and outer membranes. Three- dimensional structures of all three proteins from various bacterial species have been solved. Although this has brought us closer to understanding the efflux mechanism, much remains to be learned as to precisely how drugs are captured and expelled. When coupled to the movement of protons from periplasm to the cytoplasm, AcrB, the actual pump protein of the inner membrane, has the remarkable ability to bind to structurally diverse group of antibiotics and inhibitors and transport them to the channel protein TolC in the outer membrane. AcrA, a periplasmic lipoprotein anchored to the inner membrane, completes the assembly of the tripartite efflux pump. The two aims of this application will integrate structural and modeling dat with genetic, molecular dynamics simulations, and biochemical data to create a detailed map of drug binding and translocation sites in AcrB and reveal its structure-function plasticity. Given th conservation and active role of AcrB-like multidrug efflux pumps in human pathogens, the outcome of this application will have a broad and important impact.

 描述（由适用提供）：人类细菌病原体变为多药的令人震惊的速度是全球健康问题。尽管使用抗生素特异性的药代动力学和药效学知识来施用正确的抗生素剂量，但正在努力努力寻找新型的抗菌化合物和细胞靶标，并对耐药性机制有了更深入的了解。一种这样的机制涉及多药耐药外泵的表达升高，以抵抗在细菌包膜上的药物影响，从而赋予对多种抗生素的耐药性。在所有革兰氏阴性人类细菌病原体中均匀配置的这种药物外排泵属于耐药性 - 结构分析（RND）家族。大肠杆菌的组成型RND泵复合物包括ACRA，ACRB和TOLC蛋白，在组装时，桥接内膜和外膜。已经解决了来自各种细菌的所有三种蛋白质的三维结构。尽管这使我们更接近理解外排机制，但要准确地捕获和驱除药物还有很多待汲取的知识。当与质子从蛋白质到细胞质的运动耦合时，内膜的实际泵蛋白ACRB具有与结构上延伸的抗生素和抑制剂的结构相似的能力，并将其运输到外膜外膜中的通道蛋白TOLC。 ACRA是一种锚定在内膜上的周质脂蛋白，完成了三方外排泵的组装。该应用的两个目标将将结构和建模DAT与遗传，分子动力学模拟以及生化数据整合在一起，以创建ACRB中药物结合和易位位点的详细图表，并揭示其结构功能可塑性。考虑到类似ACRB样的多药外排泵在人类病原体中的保护和积极作用，该应用的结果将产生广泛而重要的影响。