The zero- and double-quantum methyl TROSY Hahn-echo and the methyl 1H-1H dipole-dipole cross-correlation nuclear magnetic resonance experiments enable estimation of multiple quantum chemical exchange broadening in methyl groups in proteins. The two relaxation rate constants are established to be linearly dependent using molecular dynamics simulations and empirical analysis of experimental data. This relationship allows chemical exchange broadening to be recognized as an increase in the Hahn-echo relaxation rate constant. The approach is illustrated by analyzing relaxation data collected at three temperatures for E. coli ribonuclease HI and by analyzing relaxation data collected for different cofactor and substrate complexes of E. coli AlkB.

中文翻译：

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检测大分子甲基中的化学交换。

零量子和双量子甲基TROSY Hahn-echo和甲基1H-1H偶极-偶极互相关核磁共振实验能够估算蛋白质中甲基的多个量子化学交换展宽。使用分子动力学模拟和实验数据的经验分析，将两个弛豫速率常数建立为线性相关。这种关系使得化学交换变宽被认为是哈恩-回声弛豫速率常数的增加。通过分析在三个温度下收集的大肠杆菌核糖核酸酶HI的弛豫数据，以及通过分析收集的大肠杆菌AlkB不同辅因子和底物复合物的弛豫数据来说明该方法。