The Chemistry and Biology of Galactofuranose Residues

呋喃半乳糖残基的化学和生物学

• 批准号: 8414877
• 负责人: Laura L Kiessling
• 金额: $ 33.47万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-15 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8414877
• 关键词: Address; Anabolism; Antimycobacterial Agents; Biochemical; Biogenesis; Biological Assay; Biology; Carbohydrate Chemistry; Carbohydrates; Catalysis; Cell Wall; Cells; Cessation of life; Chemicals; Chemistry; Complex; Data; Development; Diphosphates; Disease; Enzymatic Biochemistry; Enzymes; Flavins; Foundations; Galactans; Galactose; Generations; Genus Mycobacterium; Glycobiology; Glycoconjugates; Goals; Grant; Investigation; Ions; Knowledge; Length; Ligands; Link; Mediating; Methods; Microbe; Microbiology; Mutase; Mycobacterium Infections; New Agents; Organic Chemistry; Parasites; Pharmaceutical Preparations; Polymers; Polysaccharides; Process; Property; Research; Research Project Grants; Role; Spectrum Analysis; Structure; Testing; Tuberculosis; Uridine; Virulence; adduct; arabinofuranose; arabinogalactan; base; biological systems; cell growth; cofactor; covalent bond; design; frontier; fungus; inhibitor/antagonist; insight; mycobacterial; polymerization; public health relevance; pyranose; small molecule; structural biology; sugar

DESCRIPTION (provided by applicant): Galactofuranose (Galf) residues have been implicated in the virulence or viability of many microbes, including mycobacteria. The goal of the proposed research is to understand the mechanisms underlying Galf residue incorporation into the mycobacterial cell wall. We shall investigate the structure, catalytic mechanism, and function of two key enzymes in this process: the flavoenzyme uridine-5'-diphosphate (UDP)-galactopyranose mutase (Glf or UGM) and the galactosylfuranosyltransferase GlfT2. The three Specific Aims of this application follow. Aim 1 is to understand the mechanism of the flavoenzyme UGM. Elucidating the catalytic mechanism UGM will enhance our understanding of the diverse chemistry of the flavoenzymes, provide insight into the chemistry underlying cell wall biosynthesis, and guide the generation of inhibitors of this essential enzyme. Aim 2 is to generate potent and cell-permeable inhibitors of UGM that can be used as probes of cell wall biosynthesis and as leads for the development of new antimycobacterial agents. Aim 3 is to investigate the enzyme GlfT2, which catalyzes the synthesis of a galactan polymer composed of alternating 1,5- and 1,6-linked Galf residues. We shall test whether the polymerization is processive, explore how a single enzyme generates two regioisomeric sugar linkages, and determine how polymer length is controlled. These investigations will illuminate the mechanisms underlying galactan biosynthesis in mycobacteria and the biosynthesis of polysaccharides, in general. In pursuing these Aims, we shall employ methods and ideas from organic chemistry, glycobiology, carbohydrate chemistry, chemical enzymology, structural biology, microbiology, and chemical biology. Significance: The results of the proposed research will provide new insights into the assembly of the galactan polymer, an essential component of the mycobacterial cell wall. They also will address the fundamental question of how biological systems control polymer length in the absence of a template. This knowledge will be applied to develop small molecules that block mycobacterial cell growth. Such agents will serve as valuable probes of mycobacterial cell wall biosynthesis and as leads for the development of new antimycobacterial drugs.

描述（由申请人提供）：半乳核（GALF）残基与包括分枝杆菌在内的许多微生物的毒力或生存力有关。拟议的研究的目的是了解分枝杆菌细胞壁中的GALF残基掺入的机制。我们将研究两个关键酶在此过程中的结构，催化机理和功能：黄糖酶尿苷-5'-二磷酸（UDP） - 乳乙酸氨酰糖突变酶（GLF或UGM）和半乳糖基呋喃糖基转移酶Glft2。此应用程序的三个具体目标如下。目的1是了解黄酮酶UGM的机制。阐明催化机制UGM将增强我们对黄酮酶多种化学的理解，提供对化学基础细胞壁生物合成的见解，并指导这种基本酶的抑制剂的产生。 AIM 2是产生可用的UGM的有效和可渗透抑制剂，可用作细胞壁生物合成的探针，并用作开发新的抗菌剂的铅。 AIM 3是研究GLFT2的酶，该酶催化了由1,5-和1,6-链接的GALF残基组成的Galactan聚合物的合成。我们应测试聚合是否是过程中的，探索单个酶如何产生两个区域异构糖键，并确定聚合物长度如何控制。这些研究将阐明分枝杆菌中银河生物合成的机制和多糖的生物合成。在追求这些目标时，我们将采用有机化学，糖生物学，碳水化合物化学，化学酶学，结构生物学，微生物学和化学生物学的方法和思想。意义：拟议研究的结果将为银河聚合物的组装提供新的见解，这是分枝杆菌细胞壁的重要组成部分。他们还将解决在没有模板的情况下生物系统如何控制聚合物长度的基本问题。这些知识将应用于开发阻断分枝杆菌细胞生长的小分子。此类药物将作为分枝杆菌细胞壁生物合成的有价值探针，并作为开发新的抗菌药物的铅。