CARBOHYDRATE AND GLYCOPROTEIN INTERACTIONS WITH LECTINS

描述：葡萄糖蛋白和糖脂的寡糖链 正常和转化的细胞在多种疾病中被认为是受体， 包括细胞识别，粘附， 分化和致癌转化。 的组成和 寡糖的结构与细胞分化相关， 转型 凝集素是碳水化合物结合蛋白， 包括植物和动物细胞。 凝集素 与细胞识别过程有关， 和转移。 长期目标是深入了解 糖-凝集素识别相互作用在 正常和转化细胞。 凝集素与细胞表面的结合通常会导致凝集素的交联。 糖缀合物受体，包括糖蛋白和糖脂， 许多情况与细胞的生物反应有关。 某些 从糖蛋白和糖脂中分离的寡糖是 多价并与凝集素形成交联复合物。 这导致 碳水化合物-蛋白质相互作用特异性重要新维度： 也就是说，形成独特的，均匀的交联复合物之间 碳水化合物和凝集素，即使存在碳水化合物和凝集素的混合物， 分子。 交联的复合物通常是结晶的，并且易于交联。 高分辨率X射线和中子衍射研究。 具体目标 是1）确定交联的单个凝集素的原子结构 与一系列多价碳水化合物，2）研究交联 动物凝集素的交联活性，3）探索 转化细胞表面的凝集素，以及4）探测溶液 凝集素的结合特异性。 结果，反过来，将提供 凝集素-碳水化合物结构-功能关系 正常细胞和转化细胞的相互作用。

DESCRIPTION: The oligosaccharide chains of glycoproteins and glycolipids of normal and transformed cells have been implicated as receptors in a variety of biological processes, including cellular recognition, adhesion, differentiation and oncogenic transformation. The composition and structures of the oligosaccharides correlate with cell differentiation and transformation. Lectins are carbohydrate binding proteins which are found in a wide variety of organisms, including plants and animal cells. Lectins have been implicated in cellular recognition processes including apoptosis and metastasis. The long term objective is to gain insight into the structure-function roles of carbohydrate-lectin recognition interactions in normal and transformed cells. Binding of lectins to cell surfaces often leads to cross-linking of glycoconjugate receptors, including glycoproteins and glycolipids, which in many cases is related to the biological responses of cells. Certain oligosaccharides isolated from the glycoproteins and glycolipids are multivalent and form cross-linked complexes with lectins. This leads to an important new dimension of specificity in carbohydrate-protein interactions: namely, the formation of unique, homogeneous cross-linked complexes between carbohydrates and lectins, even in the presence of mixtures of the molecules. The cross-linked complexes are often crystalline and amenable to high resolution x-ray and neutron diffraction studies. The specific aims are to 1) determine the atomic structures of a single lectin cross-linked with a series of multivalent carbohydrates, 2) investigate the cross-linking activities of animal lectins, 3) explore the cross-linking activities of lectins on the surface of transformed cells, and 4) probe the solution binding specificities of lectins. The results, in turn, will provide insight into structure-function relationships of lectin-carbohydrate interactions in normal and transformed cells.