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(申请人提供)：岩藻糖化多聚糖广泛分布于真核生物和某些细菌。在哺乳动物细胞表面，它们介导了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。在病原菌和寄生虫中，岩藻糖苷调节宿主组织的黏附和定植，并调节宿主免疫反应。尽管岩藻糖化多聚糖具有明显的重要性，但其结构的复杂性和异质性严重阻碍了对其功能的分子基础的描述。目前，还没有一种简便、经济的化学方法来合成这些多糖及其结构相关的衍生物。该项目的长期目标是开发新的方法来制备结构定义的岩藻糖苷及其衍生物，并构建新的糖链阵列平台，用于全面探索岩藻糖苷与蛋白质的相互作用。在第一个授权期，我们将重点关注三个具体目标。首先，我们将开发一种通用的岩藻糖基供体--52-二磷酸-2-L-岩藻糖(GDP-岩藻糖)的制备规模化合成的通用化学酶策略，以及化学定义的岩藻糖苷及其结构相关的衍生物。我们将利用岩藻糖基激活和从细菌来源转移酶来合成岩藻糖化多糖和糖偶联物，用于它们的功能研究。使用在AIM 1中生成的岩藻糖苷文库，我们将制备一个磷脂偶联糖树状大分子的文库，并以微阵列的形式将它们整合到支持的脂质双层膜中(AIM 2)。与目前大多数阵列中发现的常规固定化单体多糖相比，平面脂质双层中的葡聚糖的流体性质，加上多价展示，更好地反映了自然界中发现的葡聚糖的呈现方式。获得结构上定义的岩藻糖苷，结合糖树枝状大分子微阵列技术，提供了一种强大、快速的手段来分析岩藻糖苷与蛋白质的相互作用，并确定有助于结合的关键结构特征。在目标3中，我们将使用这项技术来鉴定对DC-SIGN(树突状细胞特异性ICAM-3抓取非整合素)具有增强亲和力的非天然Lewis X衍生物，DC-SIGN是一种重要的内源性受体，介导抗原递呈。从这项研究中鉴定出的具有增强DC-SIGN亲和力的葡聚糖配体将在体外作为靶向元件进行测试，以将货物运送到树突状细胞。 与公共健康相关：岩藻糖化多聚糖存在于细胞表面，它们在正常生物过程中的细胞间相互作用中发挥关键作用，也在人类疾病中发挥关键作用。这项研究的目的是开发化学工具来研究岩藻糖化多糖和糖共轭化合物的生物学功能。这些工具将提高我们对这些重要的多糖如何导致癌症和炎症等疾病的理解。