NH NH VECTOR CORRELATION IN PEPTIDES BY SOLID STATE NMR

通过固态 NMR 分析肽中 NH NH 向量的相关性

• 批准号: 6118679
• 负责人: BERND REIF
• 金额: $ 2.84万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-15 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6118679
• 关键词: biological products; biomedical equipment development; biomedical resource; enzymes; technology /technique

We present a novel solid-state NMR pulse sequence to measure the NHi-NHi,, projection angle in peptides under magic angle spinning (MAS). The method is applied to the uniformly 15 N-labelled tripeptide N-Formyl-MLF. The measured angle is directly related to the backbone angles 0 and W. The same experiment can be used to restrain side chain torsion angles, e.g. in "N-labelled arginine. In larger spin systems, the projection angle permits the determination of the geometry between different secondary structure elements. The method relies on the recoupling of the NH dipolar coupling, which is correlated to the nearest neighbor using proton mediated spin diffusion. The heteronuclear interaction is recoupled using the new heteronuclear recoupling scheme T-MREV. In contrast to the conventional MREV-8, the heteronuclear dipolar interaction is not refocussed after each rotor period. This extends the dynamic range of the experiment and allows for a more accurated determinatio n of the r ecoupled interaction. Furthermore, we present here an approach to interpret the dephasing data in a quasi-analytical fashion that permits efficient extraction of molecular parameters. Knowledge of the scaling factor of the sequence is not necessary for the theoretical description of the data.

我们提出了一种新的固态核磁共振脉冲序列来测量 魔角旋转下肽中的NHi-NHi，，投影角 （MAS）。 该方法适用于均匀15 N-标记的 三肽N-甲酰-MLF。 测得的角度与 主链角为0和W。同样的实验可以用来 抑制侧链扭转角，例如在“N-标记的精氨酸中。 在 较大的自旋系统，投影角允许确定 不同二级结构元素之间的几何形状。 的 方法依赖于NH偶极耦合的再耦合， 用质子介导的自旋关联到最近邻 扩散 异源相互作用使用新的 异源再耦合方案T-MREV 相对于 传统的MREV-8，异质偶极相互作用不是 在每个转子周期后重新聚焦。 这扩展了 该实验，并允许一个更准确的测定r 耦合相互作用。 此外，我们在这里提出了一种方法， 以准分析的方式解释失相数据， 允许有效提取分子参数。 知识 序列的缩放因子对于 数据的理论描述。