MmpL3 as a target for novel anti-TB agents

MmpL3 作为新型抗结核药物的靶标

• 批准号: 10583474
• 负责人: Mary Jackson
• 金额: $ 62.83万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-15 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10583474
• 关键词: Anabolism; Antimycobacterial Agents; Antitubercular Agents; Bacillus; Basic Science; Binding; Binding Sites; Biochemical; Biochemistry; Biological Assay; Cell Wall; Cell division; Cell membrane; Cell surface; Cells; Colorado; Complex; Coupling; Cytoplasm; Deposition; Development; Drug Targeting; Drug resistance; Ethionamide; Funding; Genetic; Genus Mycobacterium; Growth; Incidence; Joints; Knowledge; Lead; Lipids; Maps; Mediating; Medicine; Membrane; Metabolism; Molecular; Molecular Probes; Multi-Drug Resistance; Multiprotein Complexes; Mycobacterium tuberculosis; Mycolic Acid; Nature; Oklahoma; Pathogenicity; Pharmaceutical Preparations; Physiological; Physiological Processes; Play; Predisposition; Process; Proteins; Protons; Reporting; Research Personnel; Research Proposals; Resistance; Role; Series; Side; Site; Structure; Synthesis Chemistry; System; Therapeutic; Time; Treatment Efficacy; Trehalose; Tuberculosis; Universities; Validation; Variant; analog; base; cell envelope; design; drug development; inhibitor; innovation; insight; interest; isoniazid; molecular dynamics; multidisciplinary; mycobacterial; non-tuberculosis mycobacteria; non-tuberculous mycobacterial infection; novel; periplasm; resistance mechanism; resistant strain; scaffold; small molecule; small molecule inhibitor; spatiotemporal; targeted treatment; yeast two hybrid system

Summary Mycolic acids are essential building blocks of the outer membrane of all mycobacteria and the interest in drugs targeting their biosynthesis and export is clearly illustrated by the therapeutic efficacy of several past and present anti-mycobacterial agents including isoniazid, ethionamide, thiacetazone and isoxyl, and a number of recently discovered small molecule inhibitors reported to inhibit the integral membrane mycolic acid transporter, MmpL3. Joint efforts by our Consortium prior to and during the previous funding period have led to the discovery of MmpL3 and to the validation of this transporter as a target of therapeutic interest. These studies further allowed us to gain the first insights into its structure, energetics and mechanisms of susceptibility and resistance to inhibitors. Despite these advances, important gaps still remain in our understanding of the translocation of mycolic acids from the cytoplasm to the periplasm and outer membrane, the precise role played by MmpL3 in this process, and the molecular mechanisms involved. Several lines of evidence indicate that the export of mycolic acids to the cell surface involves more components than the only MmpL3 protein, and that MmpL3 may act as a scaffold for a multiprotein complex coupling synthesis and export. Our preliminary evidence further indicates that MmpL3 may play a role in coordinating, at the level of the plasma membrane, the focal deposition of cell wall core constituents during cell elongation and cell division. Aim 1 of this basic research proposal is to define the nature of the MmpL3-associated machinery responsible for the efficient synthesis and export of mycolic acids in Mycobacterium tuberculosis, and to probe the involvement of MmpL3 in the spatiotemporal coordination of new cell wall deposition during cell elongation and division. Under Aim 2, a detailed biochemical examination of MmpL3 will be conducted to delineate the precise extent of mycolic acid transport mediated by MmpL3 in mycobacterial cells and to gain insight in the molecular mechanisms involved. The assays developed under this aim will further be used to probe the precise mechanism of action of MmpL3 inhibitors and associated mechanisms of resistance. In addition to providing fundamental knowledge about essential physiological processes of all mycobacteria, the results from these studies will facilitate current drug development efforts targeted to MmpL3 and could further lead to innovative therapeutic strategies targeting key metabolic processes at the intersection of cell envelope biosynthesis and cell elongation and division.

摘要 霉菌酸是所有分枝杆菌外膜的重要组成部分，也是药物研究的热点。 以它们的生物合成和输出为靶点，清楚地说明了过去和 目前的抗分枝杆菌药物包括异烟肼、乙硫酰胺、硫代乙酮和异氧基，以及一些 新近发现的小分子抑制剂可抑制整膜霉菌酸 传送器，MmpL3。我们的财团在上一个资助期之前和期间的共同努力导致 MmpL3的发现和该转运蛋白作为治疗靶点的确认。这些 进一步的研究使我们对它的结构、能量和机制有了初步的了解 对抑制剂的敏感性和抗药性。 尽管取得了这些进展，但在我们对霉菌酸易位的理解上仍然存在重要的差距。 从细胞质到周质和外膜，MmpL3在这一过程中所起的确切作用， 以及所涉及的分子机制。有几行证据表明，霉菌酸出口到 细胞表面涉及的成分比唯一的MmpL3蛋白更多，MmpL3可能作为一种 支架用于多蛋白复合体的偶联合成和输出。我们的初步证据进一步表明 MmpL3可能在细胞膜水平上起协调细胞局灶性沉积的作用。 细胞伸长和细胞分裂过程中的壁核心成分。 这项基本研究提案的目标1是界定与MmpL3相关的负责机制的性质 目的：高效合成和输出结核分枝杆菌菌丝体中的霉菌酸，并探讨其作用机理。 MmpL3参与细胞伸长过程中新细胞壁沉积的时空协调 组织。在目标2下，将对MmpL3进行详细的生化检查，以描述准确的 MmpL3介导的霉酚酸在分枝杆菌细胞中转运的程度及其分子机制 涉及的机制。在这一目标下开发的分析方法将进一步用于探索准确的 MmpL3抑制剂的作用机制及相关耐药机制。 除了提供关于所有分枝杆菌基本生理过程的基本知识外， 这些研究的结果将促进目前针对MmpL3的药物开发工作，并可能 进一步导致针对细胞交叉点的关键代谢过程的创新治疗策略 包膜生物合成和细胞伸长和分裂。