NEW METHODS IN HIGH FIELD NMR SPECTROSCOPY

它的目的是完成两个项目的工作，处理新的 生物分子高场核磁共振波谱研究的方法学。在 第一个项目，原子群的磁化率张量 在多肽和DNA双链中的存在是通过观察确定的 磁偶极分裂和电四极分裂 选定模型化合物的高场核磁共振波谱。组仍待处理 研究的是酰胺、硫化物和二硫键，以及 磷酸二酯组。获得这些值后，拆分将 对小肽和小DNA双链进行测量，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，以便进行精确的计算 耦合自旋系统在同时作用下的演化 化学位移、自旋-自旋耦合、偶极和其他形式的 松弛，并持续应用一个R.F.任意域 力量和阶段。我们正在利用这种预测能力来探索新的 涉及现场连续应用的核磁共振实验类型 (例如，CAMELSPIN)，以开发新的结构方法 生物分子研究。将对两种新方法进行评估 是连接旋转框架和实验室框架的二维光谱， 和R.F.旋转坐标系中用于选择性反转的相位调制。

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.