NMR STUDIES OF BIOLOGICALLY IMPORTANT OLIGOSACCHARIDES

描述：（来自申请人的摘要） 在生物系统的发展和维护中的重要性。他们是 发现游离于溶液中，作为糖蛋白和糖脂的成分， 细胞表面，并已牵连在不同的作用机制， 细胞过程如炎症，细胞-细胞识别和粘附， 蛋白质周转和细菌感染。寡聚体，或分子 其模拟物，正成为药物设计中更常见的靶点， 治疗人类疾病和疾病。的细胞功能 寡糖与它们的三维形状密切相关， 构象，以及这些3D结构的知识，无论是在溶液中， 在束缚状态下，对于破译潜在因素至关重要， 控制寡糖和特定细胞受体之间的识别。 该提案旨在开发基于寡糖构象的新探针， 涉及13 C和2 H的NMR参数。主要目标是全面建立 JCH和JCC标量耦合的结构依赖性，使用实验 和计算方法，并应用这些耦合来研究 O-糖苷键构象在生物学重要的范围内 13 C标记的二糖、三糖和四糖，在溶液中游离或 与寡肽相连。还将研究涉及15 N的标量耦合。 残留13 C-1H和13 C-13 C偶极耦合和残留2 H四极耦合 定向介质中的耦合和13 C化学位移各向异性，将是 作为溶液中的额外构象约束进行研究。动生 将使用分子动力学方法和这些数据来研究性能 与实验数据进行比较，以帮助解释 后者然后，研究将扩展到更大的，生物相关的 系统，包括在CD 2上发现的复杂的高甘露糖N-聚糖， IgG上的N-聚糖和DNA适体-寡糖复合物。

Description: (From the applicant's abstract) Oligosaccharides are of central importance in the development and maintenance of biological systems. They are found free in solution, as constituents of glycoproteins and glycolipids on the cell surface, and have been implicated in the mechanisms of action of diverse cellular processes such as inflammation, cell-cell recognition and adhesion, protein turnover, and bacterial infection. Oligosaccharides, or molecular mimics thereof, are becoming more frequent targets in drug design for the treatment of human illness and disease. The cellular functions of oligosaccharides are intimately related to their three-dimensional shapes or conformations, and knowledge of these 3D structures, both free in solution and in the bound state, is essential to deciphering the underlying factors that control recognition between oligosaccharides and specific cellular receptors. This proposal aims to develop new probes of oligosaccharide conformation based on NMR parameters involving 13C and 2H. Major objectives are to fully establish the structural dependencies of JCH and JCC scalar couplings using experimental and computational methods, and to apply these couplings to investigate O-glycoside linkage conformation in the range of biologically important 13C-labeled di-, tri-, and tetrasaccharides, either free in solution or tethered to oligopeptides. Scalar couplings involving 15N will also be studied. Residual 13C-1H and 13C-13C dipolar couplings and residual 2H quadrupolar couplings in oriented media, and 13C chemical shift anisotropy, will be investigated as additional conformational constraints in solution. Motional properties will be investigated using molecular dynamics methods and these data compared to experimental data in order to assist in the interpretation of the latter. Investigations will then be extended to larger, biologically relevant systems including a complex high-mannose N-glycan found on CD2, engineered N-glycans on IgG, and DNA aptamer-oligosaccharide complexes.