NEW METHODS IN HIGH FIELD NMR SPECTROSCOPY

它打算完成两个项目的工作， 生物分子的高场核磁共振光谱研究方法。在 第一个项目，原子群的磁化率张量 发生在肽和DNA双链体正在确定通过观察 的磁偶极和电四极分裂 所选模型化合物的高场NMR谱。其余各组 检查的是酰胺，硫醚和二硫键， 磷酸二酯基团。当获得这些值时，分裂将 测量小肽和小DNA双链体，以便 确定溶液中可能的构象。在第二个项目中， 我们正在开发计算方法， 一个耦合自旋系统的演化， 化学位移，自旋-自旋耦合，偶极和其他形式的 松弛和连续施加r.f.任意域 强度和阶段。我们正在利用这种预测能力来探索新的 NMR实验的类型涉及场的连续应用 (e.g. CAMELSPIN），以开发新的方法， 生物分子的研究将评估的两种新方法 是连接旋转框架和实验室框架的二维光谱， 和r.f.相位调制用于旋转坐标系中的选择性反转。

It is intended to complete work on two projects dealing with new methodology in high-field NMR spectroscopic studies of biomolecules. In the first project, the magnetic susceptibility tensors of atomic groupings occurring in peptides and DNA duplexes are being determined by observation of the magnetic dipolar and electric quadrupolar splittings in the high-field NMR spectra of selected model compounds. Groups remaining to be examined are the amide, sulfide and disulfide linkages, and the phosphodiester group. When these values have been obtained, splittings will be measured for a small peptide and for a small DNA duplex, in order to establish the possible conformations in solution. In the second project, we are developing computational methods allowing the precise calculation of the evolution of a coupled spin system under the simultaneous influence of chemical shift, spin-spin coupling, dipolar and other forms of relaxation, and continuous application of an r.f. field of arbitrary strength and phase. We are using this predictive ability to explore new types of NMR experiments involving continuous application of the field (e.g. CAMELSPIN), in order to develop new approaches to structural investigation of biomolecules. Two new approaches which will be evaluated are 2-D spectroscopy connecting the rotating frame and laboratory frame, and r.f. phase modulation for selective inversion in the rotating frame.