Bacterial and Molecular Determinants of Mycobacterial Impermeability

项目摘要 单纯性结核分枝杆菌感染的典型治疗过程包括 四种抗生素至少能维持六个月多层M. 长期以来，结核病细胞被膜与生物体内在的药物敏感性差有关。 虽然外部的“myco”膜被假设为进入抗生素的主要屏障， 在肽聚糖或细胞质中的靶点，包膜的其他方面可能起作用。此外，委员会认为， 与模式生物大肠杆菌和哺乳动物细胞相比，该领域只有 对能渗透M.结核基于 发表的和初步的数据，PI假设M。结核病不渗透性是一种 结果的信封组成以及目标位置和化学结构的 化合物.检验这一假设的一个主要障碍是缺乏高通量的工具来识别 控制化合物穿过包膜层渗透的细菌和分子因素。在这 根据该提案，PI开发并部署了两种互补的方法来定义细菌和 M的分子决定簇。结核病不透性他们将首先测试 各种M.结核因子的分子把关作用。接下来，他们将在全球范围内确定M。 结核病的基因有助于菌膜的不透性。最后，他们会 全面确定与M相关的结构基序。结核菌膜 渗透或缺乏渗透。这些目标的顺利实现将为医药学的发展奠定基础。 化学努力提高M。结核病对现有药物和新发现药物的吸收 化合物. PI用于实现这些目标的方法很容易移植到物种中， 该包膜渗透性也是治疗限制性的，例如，非结核分枝杆菌 和革兰氏阴性菌

Project Summary The typical course of treatment for uncomplicated Mycobacterium tuberculosis infection comprises four antibiotics and lasts for at least six months. The impermeability of the multi-layered M. tuberculosis cell envelope has long been linked to the organism’s intrinsically-poor drug susceptibility. While the outer ‘myco’ membrane is hypothesized to be the primary barrier to accessing antibiotic targets in the peptidoglycan or cytoplasm, other facets of the envelope likely contribute. Moreover, compared to the model organism Escherichia coli and to mammalian cells, the field has only a rudimentary understanding of the kinds of compounds that can permeate M. tuberculosis. Based on published and preliminary data, the PIs hypothesize that M. tuberculosis impermeability is a consequence of envelope composition as well as the target location and chemical structure of the compound. A major hurdle to testing this hypothesis is the lack of high-throughput tools for identifying bacterial and molecular factors that control compound permeation across envelope layers. In this proposal, The PIs develop and deploy two complementary methods for defining the bacterial and molecular determinants of M. tuberculosis impermeability. They will first test the relative importance of various M. tuberculosis factors in molecule gate-keeping. Next, they will globally determine the M. tuberculosis genes that contribute to mycomembrane impermeability. Finally, they will comprehensively determine the structural motifs associated with M. tuberculosis mycomembrane permeation or lack thereof. Successful completion of these aims will lay the foundation for medicinal chemistry efforts to improve M. tuberculosis uptake of both existing drugs and newly-discovered compounds. The methods that the PIs use to achieve these aims are easily ported to species for which envelope permeability is also treatment-limiting, e.g., non-tuberculous mycobacteria (NTMs) and Gram-negatives.