Inhibition of Glycoprotein Biosynthesis in Gram-Negative Pathogens

革兰氏阴性病原体糖蛋白生物合成的抑制

• 批准号: 8262295
• 负责人: Barbara Imperiali
• 金额: $ 4.01万
• 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: 2012-02-06 至 2013-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8262295
• 关键词: Acetyl Coenzyme A; Acetyltransferase; Acids; Acinetobacter baumannii; Address; Anabolism; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotics; Biological; Biological Assay; Campylobacter; Campylobacter jejuni; Cell Adhesion; Cell Wall; Cell surface; Cells; Cellular Assay; Chemicals; Chemistry; Communicable Diseases; Dependence; Development; Dose; Enzyme Inhibitor Drugs; Enzyme Inhibitors; Enzymes; Genes; Glycoconjugates; Glycoproteins; Goals; Gram-Negative Bacteria; HAT1 gene; Histones; Human; In Vitro; Inhibitory Concentration 50; Institutes; Lead; Lectin; Link; Lipopolysaccharides; Mammalian Cell; Membrane Glycoproteins; Methodology; Molecular; NIH 3T3 Cells; Neisseria gonorrhoeae; Pan Genus; Pathogenesis; Pathogenicity; Pathway interactions; Play; Procedures; Production; Prokaryotic Cells; Protein Glycosylation; Public Health; Publishing; Radioactivity; Reagent; Research; Resistance development; Role; Screening procedure; Structure-Activity Relationship; Therapeutic Agents; Toxic effect; Transferase; Virulence; Virulence Factors; Western Blotting; Work; antimicrobial; bacillosamine; base; combat; cross reactivity; enzyme activity; glycoprotein biosynthesis; glycosylation; high throughput screening; human HAT1 protein; in vitro Assay; inhibitor/antagonist; interest; link protein; microbial; new therapeutic target; novel; novel strategies; novel therapeutics; pathogen; pathogenic bacteria; small molecule; sugar; tool

DESCRIPTION (provided by applicant): It is well known that antibiotic resistance is a critical issue in the battle against microbial pathogens. Less well known is the way forward to new approaches in antibacterial therapy that address the serious consequences of resistance development. In the past decade bacterial cell surface glycoconjugates, including the lipopolysaccharide (LPS) component of the outer cell wall and cell surface N- and O-linked glycoproteins of several medically relevant Gram-negative bacteria pathogens, have been characterized in molecular detail and found to be essential for host-dependent virulence and pathogenicity. We propose to employ a high-throughput small-molecule screening strategy to identify potent and selective inhibitors of an essential step in the biosynthesis of di-N-acetylbacillosamine (diNAcBAc), which is a highly modified saccharide that features as an essential building block in the cell-surface glycoconjugates of many Gram-negative pathogens. The current studies target the discovery of small molecule inhibitors of the enzyme PglD, which is an acetyl-CoA-dependent acetyl transferase that carries out the final step in the conversion of UDP-GlcNAc into UDP-diNAcBac in the N-linked protein glycosylation pathway of the enteropathogen Campylobacter jejuni. Phenotypic studies establish that UDP-diNAcBac is an obligatory intermediate in the pathway that ultimately affords bacterial cell-surface N-linked glycoproteins that are involved in host cell adhesion, invasion and colonization. Therefore, smal-molecule inhibitors that result from these studies would be incisive chemical tools for elucidating the fundamental roles of highly modified saccharides in microbial virulence and pathogenesis. Additionally, the probes would represent novel leads in the development of new therapeutic agents and validate a new class of antibiotic target. This research addresses the central hypothesis that the biosynthetic pathways in pathogenic bacteria that lead to highly modified sugar building blocks, such as di-N-acetyl-bacillosamine, represent an "Achilles' heel" that can be exploited in the battle against infectious diseases. The general principles that we develop in these studies will be applicable to other microbial pathogens that implement prokaryote- specific N- and O-linked glycoproteins as virulence factors. If successful, the research will identify new enzyme targets and strategies in the global crisis of combating infectious diseases in the face of escalating antibiotic resistance.

描述（由申请人提供）：众所周知，抗生素耐药性是对抗微生物病原体的关键问题。不太为人所知的是，在抗菌治疗中，解决耐药性发展的严重后果的新方法的前进道路。在过去的十年中，细菌细胞表面糖缀合物，包括外细胞壁的脂多糖（LPS）组分和几种医学相关的革兰氏阴性细菌病原体的细胞表面N-和O-连接的糖蛋白，已经在分子细节上进行了表征，并发现对于宿主依赖性毒力和致病性是必需的。我们建议采用高通量的小分子筛选策略，以确定有效的和选择性的抑制剂的一个重要步骤，在生物合成的二-N-乙酰基杆菌胺（diNAcBAc），这是一个高度修饰的糖，功能作为一个重要的积木在许多革兰氏阴性病原体的细胞表面糖缀合物。目前的研究目标是发现酶PglD的小分子抑制剂，PglD是一种乙酰辅酶A依赖性乙酰转移酶，其在肠道病原体空肠弯曲菌的N-连接蛋白糖基化途径中进行UDP-GlcNAc转化为UDP-diNAcBac的最后一步。表型研究证实，UDP-diNAcBac是最终提供细菌细胞表面N连接糖蛋白的途径中的一种必需中间体，这些糖蛋白参与宿主细胞粘附、侵袭和定殖。因此，从这些研究中得到的小分子抑制剂将是阐明 高度修饰的β-内酰胺酶在微生物毒力和致病性中的基本作用。此外，这些探针将代表开发新治疗药物的新线索，并验证一类新的抗生素靶点。这项研究解决了一个中心假设，即致病菌中导致高度修饰的糖构建块（如二-N-乙酰基-杆菌胺）的生物合成途径代表了一个可以在对抗传染病的斗争中利用的“阿喀琉斯之踵”。我们在这些研究中开发的一般原则将适用于其他微生物病原体，这些病原体将原核生物特异性N-和O-连接糖蛋白作为毒力因子。如果成功，该研究将在面临抗生素耐药性不断升级的全球抗击传染病危机中确定新的酶靶点和策略。