Enzymatic Mechanism of Polysaccharide Length Control by GlfT2

GlfT2 控制多糖长度的酶促机制

• 批准号: 10537075
• 负责人: Alan Wylde Carter
• 金额: $ 4.68万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-18 至 2025-08-17
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10537075
• 关键词: Achievement; Anabolism; Antibiotic susceptibility; Bacteria; Bacterial Antibiotic Resistance; Bacterial Polysaccharides; Binding; Biological Assay; Biological Process; Catalysis; Cell Wall; Cells; Cellular Structures; Chemicals; Chemistry; Communication; Disease; Dissociation; Ensure; Environment; Enzyme Kinetics; Enzymes; Exhibits; Future; Galactans; Genus Mycobacterium; Glycobiology; Goals; Growth; Hydrophobicity; In Vitro; Investigation; Kinetics; Lead; Length; Life; Literature; Maps; Measures; Mediating; Modernization; Molecular; Monosaccharides; Mycobacterium leprae; Mycobacterium tuberculosis; Nature; Organism; Orthologous Gene; Physiology; Play; Polymers; Polysaccharides; Process; Production; Proteins; Research; Roentgen Rays; Role; Science; Slide; Specificity; Structure; Substrate Interaction; Substrate Specificity; Testing; Thinness; Training; Variant; Work; antibiotic design; arabinogalactan; bacterial fitness; biophysical properties; career development; combat; enzyme structure; extracellular; fitness; glycosyltransferase; human pathogen; in vitro activity; insight; macromolecule; mycobacterial; novel; periplasm; polymerization; preservation; simulation; skills; sugar

PROJECT SUMMARY/ABSTRACT Extracellular polysaccharides play critical roles across all domains of life. Bacterial polysaccharides are a diverse class of macromolecules with multiple biological functions, including mediating interactions with the external environment and preserving cell wall integrity. Bacterial glycosyltransferases are responsible for polysaccharide diversity through their differences in substrate specificity and linkage production. Polysaccharide biosynthesis and elongation can occur by multiple mechanisms; the least understood is processive polymerization. Processivity is elicited from an enzyme’s ability to retain the acceptor through numerous elongation steps. This process reduces the production of short-length polysaccharides, which could be harmful to bacterial fitness. Processivity may represent a common and critical mechanism for polysaccharide biosynthesis and length control. Production of the mycobacterial galactan by galactofuranosyltransferase 2 (GlfT2) was shown to proceed by a processive mechanism. The galactan of Mycobacterium spp. is an essential structural glycan, functioning as a component of the cell wall structure of human pathogens including Mycobacterium tuberculosis and Mycobacterium leprae. Galactan truncation decreases cell fitness, promotes periplasm thinning, and increases antibiotic susceptibility. Therefore, enzymatic processivity by GlfT2 likely ensures the galactan is of sufficient length. The proposed studies seek to define the mechanism of GlfT2 processivity and the biophysical parameters that dictate product length distributions. This project encompasses training in enzyme production and characterization, enzyme kinetics assays, and enzyme structure determination. The Kiessling group, leaders in chemical glycobiology, and the Department of Chemistry at MIT provide a rich environment to acquire these research skills. The research environment also offers opportunities to engage in science communication, literature analysis, and career development. The results from the investigations proposed are expected to provide a framework for mechanistic analysis of processive glycosyltransferases found in other bacteria and across the different domains of life. New insights into this under-characterized class of enzymes will provide novel targets to combat the modern emergence of antibiotic-resistant bacteria.

项目概要/摘要 细胞外多糖在生命的各个领域都发挥着至关重要的作用。 具有多种生物功能的不同类别的大分子，包括介导与 外部环境和保持细胞壁完整性负责。 多糖多样性通过其底物特异性和连锁产生的差异而产生。 多糖生物合成和延伸可以通过多种机制发生；最不了解的是； 持续聚合是由酶通过保留受体的能力引起的。 许多延伸步骤减少了短长度多糖的产生。 对细菌适应性有害可能是一种常见且关键的机制。 多糖生物合成和长度控制。 呋喃半乳糖基转移酶 2 (GlfT2) 生产分枝杆菌半乳聚糖的过程如下： 分枝杆菌属的半乳聚糖是一种重要的结构聚糖，具有 人类病原体细胞壁结构的组成部分，包括结核分枝杆菌和 麻风分枝杆菌截短会降低细胞适应性，促进周质变薄，并增加细胞适应性。 因此，GlfT2 的酶促持续性可能确保半乳聚糖足够。 拟议的研究旨在定义 GlfT2 持续性和生物物理学的机制。 决定产品长度分布的参数该项目包括酶生产方面的培训。 和表征、酶动力学测定和酶结构测定。 化学糖生物学领域的领导者和麻省理工学院化学系为 研究环境还提供了参与科学的机会。 沟通、文献分析和职业发展 所提出的调查结果如下。 有望为其他生物中发现的进行性糖基转移酶的机制分析提供框架 细菌和生命的不同领域对这一类未充分表征的酶的新见解。 将为对抗现代抗生素耐药细菌的出现提供新的目标。