MIRA: Probing Glycan Polymer Patterns on Bacterial Cell Surfaces

MIRA：探测细菌细胞表面的聚糖聚合物模式

• 批准号: 10275911
• 负责人: Tania Lupoli
• 金额: $ 34.28万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10275911
• 关键词: Address; Antibiotics; Area; Bacteria; Bacterial Polysaccharides; Bacterial Proteins; Bar Codes; Biochemistry; Biology; Cause of Death; Cell surface; Chemicals; Development; Environment; Epitopes; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Human; Infection; Label; Laboratories; Mediating; Membrane; Microbiology; Molecular; Molecular Chaperones; Monosaccharides; O Antigens; Oligosaccharides; Organic Chemistry; Organism; Outcome; Pathway interactions; Pattern; Planets; Polymers; Polysaccharides; Predisposition; Production; Proteins; Public Health; Reagent; Route; Skin; Structure; Surface; Work; base; biochemical tools; cell envelope; glycosyltransferase; improved; insight; interdisciplinary approach; molecular recognition; novel diagnostics; novel strategies; pathogen; pathogenic bacteria; programs; protein protein interaction; small molecule; sugar; symbiont

Project Summary/Abstract Our planet is inhabited by trillions of bacteria that live inside and outside of humans. The “skin”, or surface, of bacteria is called the cell envelope, and functions to separate us from them. Although some bacteria are symbionts, infection by pathogenic bacteria is still a major cause of death worldwide. While Gram-negative bacteria contain a protective outer membrane layer absent in most Gram-positives, almost all bacteria contain polymers composed of unique patterns of glycans that extend from the cell surface. Bacterial surface sugar polymers, or exo-polysaccharides, act as molecular barcodes that distinguish different strains of bacteria within a single species. Many bacterial exo-polysaccharides contain rare sugars, which are monosaccharides that are absent in other organisms, including humans. While exo-polysaccharides are necessary for host infection, we still lack an understanding of how rare sugar-containing glycan polymers are assembled, recognized, and enable survival in the host. My laboratory seeks to generate chemical and biochemical tools to study bacterial protein and glycan pathways that enable survival in different environments. Our main areas of focus are: (1) development of small molecule regulators of bacterial chaperone function; (2) manipulation of cell surface sugar patterns to selectively label and disable bacteria. This proposal focuses on the latter program, in which we identify rare saccharide subunits that are unique to Gram-negative cell surface polymers called O-antigens, and represent key epitopes that mediate interactions with hosts and susceptibility to antibiotics. Over the next five years, we will address the following questions: (1) Can we improve chemoenzymatic routes to rare sugar precursor substrates? (2) How do glycosyltransferases recognize rare sugar substrates to build O-antigens? (3) Are O-antigen glycosyltransferases regulated via protein-protein interactions? (4) What host protein structural motifs are involved in bacterial rare sugar recognition? (5) Can we identify new host proteins involved in bacterial recognition? To answer these questions, we will use a multidisciplinary approach, involving a combination of organic chemistry, chemical biology, biochemistry, microbiology and sequencing-based analyses. This work will significantly expand our understanding of cellular mechanisms underlying bacterial polysaccharide synthesis, and will teach us how humans recognize foreign sugars. Relevance to public health: In addition to providing fundamental insight into the production of bacterial factors that are important for infection, the results of this proposal will inform novel strategies to disable hard-to-treat Gram-negative infections by interference of essential host-pathogen interactions, as well as biomolecular reagents to recognize bacterial oligosaccharide structures for new diagnostics.

项目摘要/摘要 我们的星球受到人类内外的数万亿个细菌的影响。 “皮肤”或 细菌的表面称为细胞包膜，功能可将其与它们分开。虽然有些细菌 是符号，致病细菌感染仍然是全球死亡的主要原因。而革兰氏阴性 细菌在大多数革兰氏阳性中都没有受保护的外膜层，几乎所有细菌都包含 聚合物由从细胞表面延伸的聚糖的独特模式组成。细菌表面糖 聚合物或外部 - 丙糖浆充当分子条形码，区分不同的细菌菌株 一个物种。许多细菌外的外糖浆含有稀有糖，这是单糖的 在包括人类在内的其他生物体中不存在。虽然宿主感染是必需的，但我们 仍然缺乏了解少于少量含糖的聚糖聚合物组装，识别和启用的理解 主持人的生存。 我的实验室试图生成化学和生化工具来研究细菌蛋白和聚糖 可以在不同环境中生存的途径。我们的主要重点领域是：（1）开发小型 细菌链酮功能的分子调节剂； （2）操纵细胞表面糖图案以选择性 标签和禁用细菌。该提案重点介绍了后一个计划，我们在其中确定了稀有的2糖 革兰氏阴性细胞表面聚合物称为O-抗原的亚基，代表关键表位 介导与宿主的相互作用和对抗生素的敏感性。在接下来的五年中，我们将解决 以下问题：（1）我们可以改善稀有糖前体底物的化学酶途径吗？ （2）如何 糖基转移酶是否识别稀有的糖基质来构建O-抗原？ （3）是O-抗原 通过蛋白质 - 蛋白质相互作用调节的糖基转移酶？ （4）哪种宿主蛋白​​结构基序是 参与细菌稀有糖识别？ （5）我们可以识别涉及细菌的新宿主蛋白 认出？为了回答这些问题，我们将使用多学科的方法，涉及 有机化学，化学生物学，生物化学，微生物学和基于测序的分析。这项工作将 显着扩展我们对细菌多糖合成的细胞机制的理解， 并将教会我们人类如何识别外国糖。 与公共卫生有关：除了提供细菌工厂生产的基本见解 对于感染很重要，该提案的结果将为您提供新的策略，以禁用难以治疗 革兰氏阴性感染通过干扰必需的宿主 - 病原体相互作用以及生物分子 识别用于新诊断的细菌寡糖结构的试剂。