Separating Structure and Dynamics in CSA/DD Cross-Correlated Relaxation: A Case Study on Trehalose and Ubiquitin
✍ Scribed by Katalin E Kövér; Gyula Batta
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 215 KB
- Volume
- 150
- Category
- Article
- ISSN
- 1090-7807
No coin nor oath required. For personal study only.
✦ Synopsis
We present two new sensitivity enhanced gradient NMR experiments for measuring interference effects between chemical shift anisotropy (CSA) and dipolar coupling interactions in a scalar coupled two-spin system in both the laboratory and rotating frames. We apply these methods for quantitative measurement of longitudinal and transverse cross-correlation rates involving interference of 13 C CSA and 13 C-1 H dipolar coupling in a disaccharide, α,α-D-trehalose, at natural abundance of 13 C as well as interference of amide 15 N CSA and 15 N-1 H dipolar coupling in uniformly 15 N-labeled ubiquitin. We demonstrate that the standard heteronuclear T 1 , T 2 , and steady-state NOE autocorrelation experiments augmented by cross-correlation measurements provide sufficient experimental data to quantitatively separate the structural and dynamic contributions to these relaxation rates when the simplifying assumptions of isotropic overall tumbling and an axially symmetric chemical shift tensor are valid.