Chemical tools for studying fucosylated glycans

研究岩藻糖基化聚糖的化学工具

• 批准号: 8535787
• 负责人: Peng Wu
• 金额: $ 30.13万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8535787
• 关键词: Adhesions; Antigen Presentation; Avidity; Bacteria; Binding; Biological Process; Cell Adhesion; Cell Communication; Cell surface; Cells; Chemicals; Chemistry; Coupled; Dendritic Cells; Diphosphates; Disease; Elements; Embryonic Development; Enzymes; Eukaryota; Fertilization; Fucose; Fucosyltransferase; Glycoconjugates; Goals; Grant; Guanidines; Guanosine Diphosphate Fucose; Heterogeneity; Immune response; Inflammation; Libraries; Ligands; Lipid Bilayers; Lipids; Liposomes; Liquid substance; Lymphocyte antigen CD50; Malignant Neoplasms; Mammalian Cell; Mediating; Methods; Microarray Analysis; Molecular; Nature; Neoplasm Metastasis; Organism; Parasites; Pathologic Processes; Phospholipids; Physiological Processes; Play; Polysaccharides; Preparation; Process; Proteins; Research; Source; Surface; Technology; Testing; Tissues; analog; angiogenesis; base; cost; cost effective; directed evolution; expression cloning; fucokinase; galactoside 3-fucosyltransferase; human disease; improved; in vitro testing; pathogenic bacteria; public health relevance; receptor; tool; tumor

DESCRIPTION (provided by applicant): Fucosylated glycans are widely distributed throughout eukaryotes and certain bacteria. On the surface of mammalian cells, they mediate a variety of physiological and pathological processes, including angiogenesis, fertilization, embryogenesis, inflammation, and tumor metastasis. In pathogenic bacteria and parasites, fucosides regulate adhesion and colonization of host tissues and modulate the host immune response. Despite the obvious importance of fucosylated glycans, delineating the molecular basis of their function is severely hampered by their structural complexity and heterogeneity. Currently, there is no facile and cost-effective chemistry for synthesizing these glycans and their structurally related derivatives. The long term goal of this project is to develop new methods for the preparation of structurally defined fucosides and their derivatives and to fabricate new glycan array platforms for the comprehensive exploration of fucoside- protein interactions. In the first granting period, we will focus on three specific aims. First, we will develop a general chemoenzymatic strategy for preparative-scale synthesis of the universal fucosyl donor, guanidine 52- diphosphate-2-L-fucose (GDP-fucose), as well as chemically defined fucosides and their structurally related derivatives. We will harness fucosyl activation and transfer enzymes from bacterial sources to synthesize fucosylated glycans and glycoconjugates for their functional studies. Using the fucoside libraries generated in Aim 1, we will prepare a library of phospholipid-conjugated glycodendrimers and incorporate them into supported lipid bilayer membranes in a microarray format (Aim 2). The fluid nature of glycans in the planar lipid bilayer, coupled with the multivalent display, better mirrors the presentation of glycans found in nature as compared to the conventional immobilized monomeric glycans found in most arrays today. Access to structurally defined fucosides combined with the glycodendrimer microarray technology provides a powerful, rapid means to profile fucoside-protein interactions and to identify key structural features contributing to binding. In Aim 3, we will use this technology to identify unnatural Lewis X derivatives with enhanced avidity for DC-SIGN (dendritic cell-specific ICAM-3-grabbing nonintegrin), an important endocytic receptor mediating antigen presentation. The glycan ligands with enhanced DC-SIGN avidity identified from this study will be tested in vitro as targeting elements for delivering cargos to dendritic cells. PUBLIC HEALTH RELEVANCE: Fucosylated glycans are found on cell surfaces, where they play key roles in cell-cell interactions involved in normal biological processes and also in human disease. The goal of this research is to develop chemical tools for studying the biological functions of fucosylated glycans and glycoconjugates. These tools will improve our understanding of how these important glycans contribute to diseases such as cancer and inflammation.

描述（由申请人提供）：岩藻糖基化聚糖广泛分布于真核生物和某些细菌中。在哺乳动物细胞表面，它们介导多种生理和病理过程，包括血管生成、受精、胚胎发生、炎症和肿瘤转移。在病原细菌和寄生虫中，岩藻糖苷调节宿主组织的粘附和定植，并调节宿主免疫反应。尽管岩藻糖基化聚糖具有明显的重要性，但其结构复杂性和异质性严重阻碍了其功能的分子基础的描述。目前，还没有简便且经济有效的化学方法来合成这些聚糖及其结构相关的衍生物。该项目的长期目标是开发制备结构明确的岩藻糖苷及其衍生物的新方法，并构建新的聚糖阵列平台以全面探索岩藻糖苷-蛋白质相互作用。 在第一个资助期内，我们将重点关注三个具体目标。首先，我们将开发通用化学酶策略，用于制备规模合成通用岩藻糖基供体、52-二磷酸胍-2-L-岩藻糖（GDP-岩藻糖）以及化学定义的岩藻糖苷及其结构相关的衍生物。我们将利用细菌来源的岩藻糖基活化和转移酶来合成岩藻糖基化聚糖和糖缀合物，用于其功能研究。 使用目标 1 中生成的岩藻糖苷文库，我们将制备磷脂缀合的糖树枝状聚合物文库，并将它们以微阵列形式整合到支持的脂质双层膜中（目标 2）。与当今大多数阵列中发现的传统固定化单体聚糖相比，平面脂质双层中聚糖的流体性质与多价显示相结合，更好地反映了自然界中发现的聚糖的呈现。获得结构明确的岩藻糖苷与糖树枝状聚合物微阵列技术相结合，提供了一种强大、快速的方法来分析岩藻糖苷-蛋白质相互作用并确定有助于结合的关键结构特征。在目标 3 中，我们将使用该技术来鉴定非天然 Lewis X 衍生物，该衍生物对 DC-SIGN（树突状细胞特异性 ICAM-3 捕获非整联蛋白）具有增强的亲和力，DC-SIGN 是介导抗原呈递的重要内吞受体。本研究中鉴定出的具有增强的 DC-SIGN 亲和力的聚糖配体将作为将货物递送至树突状细胞的靶向元件进行体外测试。 公共卫生相关性：岩藻糖基化聚糖存在于细胞表面，在正常生物过程以及人类疾病中的细胞间相互作用中发挥着关键作用。这项研究的目标是开发化学工具来研究岩藻糖基化聚糖和糖复合物的生物学功能。这些工具将提高我们对这些重要聚糖如何导致癌症和炎症等疾病的理解。