Unraveling Bacterial Cell Wall Biosynthesis and Sensing via Synthetic Analogs

项目摘要 在美国，超过200万人患有对FDA批准的抗生素耐药的细菌感染。 每年的国家。其中，超过20，000名患者死于这些感染。激增 耐药细菌已成为一种日益严重的流行病，并有可能破坏人类在 过去几十年。事实证明，由于各种原因，很难发现新的抗生素，包括在 开发了与细菌目标相关的概念。提高我们设计和发现新工具的能力， 为了对抗细菌感染，更好地了解它们的生物学变得很重要。细菌细胞壁是 抗生素的无可匹敌的目标，包括许多临床相关药物的目标。然而， 细菌细胞壁组装及其与宿主生物体相互作用的基本方面仍然存在很大的差异。 探索不足。我们的实验室在设计细胞壁类似物方面具有丰富的经验， 在细胞壁生长和分裂期间由细菌细胞加工。在这些底物类似物中，我们引入 非原生标签（例如，点击化学手柄、生物素、荧光团），其可以被利用来阐明 支持细胞壁生物学的过程。 对于本提案，我们将把这些策略应用于两个主要领域： 肽聚糖（细菌细胞壁的主要成分）的加工和测定方法的发展 报告了革兰氏阳性菌细胞表面组分的可及性。肽聚糖是一种 由独特的结构单元组成的单个大生物大分子，包括称为 茎肽我们的实验室在标记活细菌的细胞壁方面有着丰富的经验， 表位代谢标记和位点选择性标记将成为阐明肽聚糖位点的基础 修饰，并且将是可及性测定的锚点。通过这些调查，我们预测 我们将增加对细胞壁生物合成的了解，这可以促进药物的发现和开发。

PROJECT SUMMARY Over two million people are afflicted with bacterial infections resistant to FDA-approved antibiotics in the United States every year. Of those, more than 20,000 of these patients die as a result of these infections. The surge in drug-resistant bacteria has become a growing pandemic and threatens to undermine medical gains made in the last several decades. It has proven difficult to discover new antibiotics for a myriad of reasons, including under developed concepts related to bacterial targets. To improve our ability to design and discover novel tools to combat bacterial infections, it becomes important to better understand their biology. Bacterial cell walls are unmatched targets for antibiotics, including being the target of many of clinically relevant agents. Yet, foundational aspects of bacterial cell wall assembly and its interaction with the host organisms remain vastly under explored. Our laboratory has extensive experience in designing cell wall analogs that become metabolic processed by bacterial cells during cell wall growth and division. Within these substrate analogs, we introduce non-native tags (e.g., click chemistry handles, biotin, fluorophores) that can be leveraged to elucidate the processes underpinning cell wall biology. For this proposal, we will apply these strategies towards two main areas: the development of probes related to the processing of peptidoglycan, a primary component of bacterial cell wall and to the development of assays that report on the accessibility of components on the cell surface of Gram-positive bacteria. Peptidoglycan is a single large biomacromolecule composed of unique building blocks, including a short peptidic fragment called stem peptide. Our laboratory has extensive experience in labeling cell wall of live bacteria to install unnatural epitopes. The metabolic and site-selective labeling will be the basis for elucidating sites of peptidoglycan modifications and will be the anchor point for the accessibility assay. Through these investigations, we project that we will add insight into cell wall biosynthesis that can empower drug discovery and development.