Cross-correlated relaxation rates between protein backbone H–X dipolar interactions
The relaxation interference between dipole–dipole interactions of two separate spin pairs carries structural and dynamics information. In particular, when compared to individual dynamic behavior of those spin pairs, such cross-correlated relaxation (CCR) rates report on the correlation between the spin pairs. We have recently mapped out correlated motion along the backbone of the protein GB3, using CCR rates among and between consecutive HN–N and Hα–Cα dipole–dipole interactions. Here, we provide a detailed account of the measurement of the four types of CCR rates. All rates were obtained from at least two different pulse sequences, of which the yet unpublished ones are presented. Detailed comparisons between the different methods and corrections for unwanted pathways demonstrate that the averaged CCR rates are highly accurate and precise with errors of 1.5–3% of the entire value ranges.
KeywordsBackbone motion Cross-correlated relaxation CCR GB3 Order parameter Zero-quantum coherence Double-quantum coherence Multiple-quantum coherence
This work was supported by a start-up package at the University of Colorado Denver and the Swiss National Science Foundation with Grant 140214 to B.V.
- Cavanagh J, Fairbrother WJ, Palmer AG, Rance M, Skleton NJ (2007) Protein NMR spectroscopy. Principles and pratice. Academic Press, San DiegoGoogle Scholar
- Pelupessy P, Chiarparin E, Ghose R, Bodenhausen G (1999b) Simultaneous determination of Phi and Psi angles in proteins from measurements of cross-correlated relaxation effects. J Biomol NMR 14:277–280Google Scholar