Structural Analysis of Multidrug Transport

多药物转运的结构分析

• 批准号: 7104908
• 负责人: MARK E. GIRVIN
• 金额: $ 31.93万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7104908
• 关键词: Staphylococcus aureus; bacterial proteins; conformation; glutamates; inhibitor /antagonist; micelles; multidrug resistance; nuclear magnetic resonance spectroscopy; pharmacokinetics; protein kinase A; protein structure function; protonation

DESCRIPTION (provided by applicant): Bacteria have developed several methods to resist the lethal effects of antibiotics. The broadest spectrum resistance results from the action of Multidrug resistant pumps (MDRs), which extrude a range of compounds of quite diverse chemical structure. The Small Multidrug Resistance pumps (SMRs) are 100- 110 residue dimeric proton-drug antiporters that contain the full multidrug transport machinery, stripped to its barest essentials. Hence they are ideal transporters for a comprehensive structural and functional understanding of drug transport and inhibition in a medically important MDR. We propose to determine the structures of the conformations making up the functional cycle of an SMR, and identify the binding determinants for multiple drugs and inhibitors using solution NMR by: 1) Determining the structure of a dimeric SMR in lysolipid micelles in its protonated state, 2) Measuring the affinities of multiple drugs and inhibitors above and below the pKa of the glutamate essential for transport, 3) Identifying the binding determinants for inhibitors and transportable drugs, and 4) Determining the conformational changes induced by substrate and inhibitor binding, and by deprotonation of the critical glutamate. In addition to the MDR pumps, membrane proteins are responsible for transmembrane signaling, energy transduction, and ion and metabolite transport. These proteins are important in infectious disease, genetic disorders, and cancer. Despite their importance, and the need for structure to understand their function, relatively few such structures are available. For transporters and receptors, ligand binding and transport involve multiple conformations and dynamic changes. Solution NMR is an ideal method for examining these processes. Firmly establishing NMR methods to study larger helical membrane proteins - here a dimer with total of eight transmembrane helices, will have as long-term an impact as the specific findings for an SMR.

描述（由申请人提供）：细菌已经开发了几种抗抗生素致命作用的方法。最广泛的耐药性是由多抗抗性泵（MDR）的作用引起的，该泵（MDR）挤出了一系列化合物的化学结构相当多样化的化合物。小型多药电阻泵（SMR）是100-110个残基二聚体质子质子抗管剂，其中包含完整的多重运输机械，剥夺了其最重要的必需品。因此，它们是对医学重要的MDR中药物转运和抑制的全面结构和功能理解的理想转运蛋白。我们建议确定构成SMR功能周期的构象的结构，并使用溶液使用溶液NMR确定多个和抑制剂的结合决定因素：1）确定在其质子化状态下溶糖胶束中二聚体SMR的结构，2）测量多个药物和下方抑制剂的固定率，以识别多个plut pecka和以下抑制剂的固定率。抑制剂和可运输药物的决定因素，以及4）确定底物和抑制剂结合引起的构象变化，以及通过临界谷氨酸的去质子化。 除MDR泵外，膜蛋白还负责跨膜信号传导，能量转导以及离子和代谢物转运。这些蛋白质在传染病，遗传疾病和癌症中很重要。尽管它们的重要性以及结构需要了解其功能，但相对较少的结构可用。对于转运蛋白和受体，配体结合和转运涉及多种构象和动态变化。解决方案NMR是检查这些过程的理想方法。牢固地建立了研究更大的螺旋膜蛋白的NMR方法 - 在这里，具有八个跨膜螺旋的二聚体将与SMR的特定发现一样长。