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）：岩藻糖基化的聚糖广泛分布在整个真核生物和某些细菌中。在哺乳动物细胞的表面上，它们介导了各种生理和病理过程，包括血管生成，受精，胚胎发生，炎症和肿瘤转移。在致病细菌和寄生虫中，偶生糖苷调节宿主组织的粘附和定殖并调节宿主免疫反应。尽管岩藻糖基化的聚糖显而易见，但描述其功能的分子基础受到结构上的复杂性和异质性的严重阻碍。目前，没有用于合成这些聚糖及其结构相关的衍生物的便利和成本效益的化学。该项目的长期目标是开发新方法，以制备结构定义的Fucosides及其衍生物，并制造新的聚糖阵列平台，以全面探索岩藻糖苷 - 蛋白质相互作用。 在第一个授予期内，我们将重点关注三个特定目标。首先，我们将制定一种通用的化学酶策略，用于对普遍的葡萄糖基供体的制备尺度合成，鸟苷52-二磷酸-2-L-观糖（GDP-观糖）以及化学定义的葡萄糖剂及其结构相关的衍生物。我们将利用岩藻糖基活化并将酶从细菌来源转移，以合成岩藻糖基化的聚糖和糖缀合物进行功能研究。 使用AIM 1中生成的岩藻糖苷库，我们将准备一个磷脂偶联的糖胶合体的库，并将它们掺入以微阵列格式的支持的脂质双层膜中（AIM 2）。与当今大多数阵列中发现的常规固定固定的单体聚糖相比，平面脂质双层中聚糖的流体性质与多价显示器相结合。访问结构定义的Fucosides结合了糖化二聚体微阵列技术，提供了一种强大的快速手段来介绍岩藻糖苷 - 蛋白质相互作用，并确定有助于结合的关键结构特征。在AIM 3中，我们将使用这项技术来识别DC-SIGN（树突状细胞特异性ICAM-3-抓蛋白）具有增长的不自然的Lewis X衍生物，这是一种重要的内吞受体介导的抗原表现。从这项研究中鉴定出的具有增强的DC符号亲和力的聚糖配体将在体外测试，作为将碳传递给树突状细胞的靶向元素。 公共卫生相关性：在细胞表面上发现了岩藻糖基化的聚糖，它们在正常生物学过程中涉及的细胞 - 细胞相互作用中起着关键作用，在人类疾病中也起着关键作用。这项研究的目的是开发用于研究岩藻糖基化聚糖和糖缀合物的生物学功能的化学工具。这些工具将提高我们对这些重要的聚糖如何对癌症和炎症等疾病做出贡献的理解。