NMR STUDIES OF BIOLOGICALLY IMPORTANT OLIGOSACCHARIDES

描述：(摘自申请者的摘要)低聚糖是中央 在开发和维护生物系统方面的重要性。他们是 游离于溶液中，作为糖蛋白和糖脂的组成成分 细胞表面，并已涉及多种作用机制的不同 炎症、细胞-细胞识别和黏附等细胞过程， 蛋白质周转和细菌感染。低聚糖，或分子 其模拟物正成为药物设计中越来越常见的目标 治疗人类疾病和疾病。的细胞功能 低聚糖与它们的三维形状或 构象和这些3D结构的知识，在溶液中和 在束缚状态下，对于破译潜在因素是必不可少的 低聚糖和特定细胞受体之间的控制识别。 这项建议旨在开发基于低聚糖构象的新的探针 ~(13)C和~2H的核磁共振参数。主要目标是全面建立 用实验方法研究JCH和JCC标量耦合的结构相关性 和计算方法，并应用这些耦合来研究 具有重要生物学意义的O-糖苷链构象 ~(13)C标记的二糖、三糖和四糖，在溶液中或 拴在低聚肽上。还将研究涉及15N的标量耦合。 剩余13C-1H和13C-13C偶极耦合和剩余2H四极耦合 定向介质中的耦合和13C化学位移各向异性将是 作为溶液中的附加构象约束进行了研究。情绪化 性质将使用分子动力学方法和这些数据进行研究 与实验数据进行比较，以帮助解释 后者。然后，调查将扩展到更大的、与生物相关的 包括CD2上发现的复杂高甘露糖N-葡聚糖的系统，工程设计 免疫球蛋白和DNA适体-寡糖复合体上的N-糖链。

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.