Inhibition of Prokaryote-Specific Saccharide Biosynthesis in Microbial Pathogens

微生物病原体中原核生物特异性糖生物合成的抑制

• 批准号: 9004701
• 负责人: Barbara Imperiali
• 金额: $ 4.89万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9004701
• 关键词: Achievement; Acids; Address; Adherence; Amino Sugars; Anabolism; Animal Model; Animals; Attenuated; Binding Sites; Biocompatible; Bioinformatics; Biological; Biological Assay; Campylobacter jejuni; Carbohydrates; Cell surface; Cells; Chemicals; Communicable Diseases; Development; Elements; Employee Strikes; Enzymes; Eukaryota; Family member; Fimbriae Proteins; Foundations; Future; Genetic; Glycoconjugates; Glycoproteins; Goals; HSV glycoprotein C; Health; Human; In Vitro; Indium; Infection; Intestines; Knowledge; Lead; Ligands; Light; Link; Mediating; Membrane Glycoproteins; Methods; Microbe; Modification; Monosaccharides; Neisseria gonorrhoeae; Organism; Outcome; Pathogenesis; Pathogenicity; Pathway interactions; Phenotype; Polysaccharides; Production; Prokaryotic Cells; Property; Protein Glycosylation; Proteins; Reaction; Reagent; Relative (related person); Research; Research Support; Role; Sequence Homology; Severities; Sialic Acids; Structure; System; Targeted Research; Transferase; Validation; Virulence; Virulence Factors; analog; bacillosamine; base; cell motility; design; enzyme biosynthesis; fascinate; genetic approach; glycoprotein biosynthesis; glycosylation; in vivo; inhibitor/antagonist; insight; microbial; microorganism; pathogen; prototype; small molecule; sugar; targeted sequencing; tool

DESCRIPTION (provided by applicant): Glycans decorating N- and O-linked glycoproteins, which constitute critical elements of the cell-surface landscape of many Gram-negative pathogens, integrate a variety of prokaryote-specific carbohydrates including di-N-acetyl bacillosamine (diNAcBac) and pseudaminic acid (Pse). There is growing genetic and biological evidence that modified saccharides, such as diNAcBac and Pse, are essential elements in the prokaryotic glycoconjugate repertoire and that cell surface glycoproteins that feature these sugars, serve as virulence factors, which mediate pathogen-host interactions and contribute to the severity of microbial infections. Previous studies have highlighted the fact that there is a striking diversity of monosaccharides in prokaryotes, relative to eukaryotes, however, there is a major unmet need for synthetic small molecule inhibitors that can be used as selective tools to acutely perturb their biosynthesis to understand the associations between modified sugars and bacterial pathogenicity. The proposed research involves fragment-based inhibitor design and structure-guided ligand optimization approaches together with incisive in vitro and in vivo analyses in the development of inhibitors of amino sugar acetyl transferases that catalyze key steps in the biosynthesis of UDP-diNAcBac and CMP-Pse. DiNAcBac and Pse are particularly prevalent microbial carbohydrates, which feature in the N- and O-linked glycoproteins of C. jejuni, A. baumannii and N. gonorrhoeae. These microbial pathogens are the targets of this research due to the established connections between protein glycosylation and virulence. We propose that small molecule inhibitors that acutely inhibit essential early steps in glycoprotein biosynthesis will allow for temporal control of glycoprotein biosynthesis that is not feasible with genetic approaches alone. Such inhibitors will be valuable new chemical tools that can provide insight into the effects of acutely inhibiting glycoprotein biosynthesis on motility, adherence and invasion in the native pathogen and in a pathogen/host context. The availability of inhibitors with appropriate biological properties will also validate the essentiality of carbohydrate modifications on microbial virulence in microorganisms (C. jejuni and N. gonorrhoeae) where genetic phenotyping and animal studies have provided clear evidence of the connections between glycosylation and virulence. This research will form a foundation for the application of similar strategic approaches with other pathogens that threaten human health where bioanalytical and bioinformatics approaches have been employed to predict the existence of glycoproteins that include highly modified carbohydrate building blocks. Ultimately we will address the central hypothesis that the enzymes that catalyze formation of unusual microbe-specific carbohydrate building blocks represent an "Achilles' heel" that can be exploited in the development of agents that can attenuate the virulence of serious human pathogens, which can be exploited in the battle against infectious diseases.

描述（由申请人提供）：修饰N-和O-连接糖蛋白的聚糖，构成许多革兰氏阴性病原体细胞表面景观的关键要素，整合了多种原核生物特异性碳水化合物，包括二-N-乙酰基杆菌胺（diNAcBac）和假氨基酸（Pse）。越来越多的遗传和生物学证据表明，修饰的糖蛋白，如diNAcBac和Pse，是原核糖缀合物库中的必需元件，并且以这些糖为特征的细胞表面糖蛋白充当毒力因子，其介导病原体-宿主相互作用并导致微生物感染的严重性。以前的研究已经强调了这样一个事实，即相对于真核生物，原核生物中存在单糖的惊人多样性，然而，对于合成的小分子抑制剂存在重大的未满足的需求，所述小分子抑制剂可以用作选择性工具以剧烈干扰它们的生物合成，以了解修饰的糖与细菌致病性之间的关联。 拟议的研究涉及基于片段的抑制剂设计和结构指导的配体优化方法，以及在开发氨基糖乙酰基转移酶抑制剂中的精辟的体外和体内分析，这些酶催化UDP-diNAcBac和CMP-Pse生物合成中的关键步骤。DiNAcBac和Pse是特别普遍的微生物碳水化合物，它们在C. jejuni、空肠钩口线虫A. baumannii和N.淋病这些微生物病原体是本研究的目标，由于蛋白质糖基化和毒力之间建立的联系。 我们提出，急性抑制糖蛋白生物合成中必要的早期步骤的小分子抑制剂将允许糖蛋白生物合成的时间控制，这是不可行的。 只有遗传学方法。此类抑制剂将是有价值的新化学工具，其可以提供对急性抑制糖蛋白生物合成对运动性、粘附性和免疫原性的影响的深入了解。 入侵的天然病原体和病原体/宿主的情况下。抑制剂的可用性， 适当的生物学特性也将证实碳水化合物修饰的必要性 在微生物中的微生物毒力（C. jejuni和N.淋病），其中遗传表型和动物研究提供了糖基化和毒力之间联系的明确证据。这项研究将为对威胁人类健康的其他病原体应用类似的战略方法奠定基础，其中生物分析和生物信息学方法已用于预测包括高度修饰的碳水化合物构建块的糖蛋白的存在。最终，我们将解决中心假设，即催化形成不寻常的微生物特异性碳水化合物构建块的酶代表了“阿喀琉斯之踵”，可以用于开发能够减弱严重人类病原体毒力的药物，这些药物可以用于对抗传染病。