Recent methyl adiabatic relaxation dispersion experiments provide examination of conformational dynamics across a very wide timescale (102-105 s-1) and, particularly, provide insight into the hydrophobic core of proteins and allosteric effects associated with modulators. The experiments require efficient decoupling of 1H and 13C spin interactions, and some artifacts have been discovered, which are associated with the design of the proton decoupling scheme. The experimental data suggest that the original design is valid; however, pulse sequences with either no proton decoupling or proton decoupling with imperfect pulses can potentially exhibit complications in the experiments. Here, we demonstrate that pulse imperfections in the proton decoupling scheme can be dramatically alleviated by using a single composite π pulse and provide pure single-exponential relaxation data. It allows the opportunity to access high-quality methyl adiabatic relaxation dispersion data by removing the cross-correlation between dipole-dipole interaction and chemical shift anisotropy. The resulting high-quality data is illustrated with the binding of an allosteric modulator (G2BR) to the ubiquitin conjugating enzyme Ube2g2.

中文翻译：

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在甲基绝热弛豫实验中通过伪影抑制实现纯自旋效应。


最近的甲基绝热弛豫分散实验提供了在很宽的时间尺度（102-105 s-1）内的构象动力学检查，特别是，提供了对蛋白质疏水核心和与调节剂相关的变构效应的深入了解。该实验需要有效解耦 1H 和 13C 自旋相互作用，并且已经发现了一些与质子解耦方案的设计相关的伪影。实验数据表明原设计是有效的；然而，没有质子解耦或质子解耦不完美的脉冲序列可能会在实验中表现出复杂性。在这里，我们证明了通过使用单个复合 π 脉冲可以显着减轻质子解耦方案中的脉冲缺陷，并提供纯单指数弛豫数据。它允许通过消除偶极-偶极相互作用和化学位移各向异性之间的互相关来获得高质量的甲基绝热弛豫色散数据。通过变构调节剂 (G2BR) 与泛素结合酶 Ube2g2 的结合来说明所得的高质量数据。