Vugmeyster Liliya, Perazzolo Chiara, Wist Julien, Frueh Dominique, Bodenhausen Geoffrey
Institut de chimie moléculaire et biologique, Ecole Polytechnique Fédérale de Lausanne, BCH, 1015 Lausanne, Switzerland.
J Biomol NMR. 2004 Feb;28(2):173-7. doi: 10.1023/B:JNMR.0000013828.58005.8a.
Cross-correlated fluctuations of isotropic chemical shifts can provide evidence for slow motions in biomolecules. Slow side-chain dynamics have been investigated in (15)N and (13)C enriched ubiquitin by monitoring the relaxation of C(alpha)-C(beta) two-spin coherences (Frueh et al., 2001). This method, which had hitherto been demonstrated only for protonated ubiquitin, has now been applied to both protonated and deuterated proteins. Deuteration reduces the dipole-dipole contributions to the DD/DD cross-correlation, thus facilitating the observation of subtle effects due to cross-correlation of the fluctuations of the isotropic (13)C chemical shifts. The decays of double- and zero-quantum coherences are significantly slower in the deuterated protein than in the protonated sample. Slow motions are found both in loops and in secondary structure elements.
各向同性化学位移的交叉相关涨落可为生物分子中的慢运动提供证据。通过监测Cα-Cβ双自旋相干性的弛豫，已在富含（15）N和（13）C的泛素中研究了慢侧链动力学（弗吕厄等人，2001年）。该方法迄今仅在质子化泛素中得到证实，现在已应用于质子化和氘代蛋白质。氘代减少了偶极-偶极对DD/DD交叉相关的贡献，从而便于观察由于各向同性（13）C化学位移涨落的交叉相关引起的细微效应。氘代蛋白质中双量子和零量子相干性的衰减明显比质子化样品中慢。在环区和二级结构元件中均发现了慢运动。
