A new progress in amide 1H CSA study

Dr. Lishan Yao from QIBEBT and Dr. Ad Bax from NIH jointly published a paper titled “The impact of hydrogen bonding on amide 1H chemical shift anisotropy studied by cross-correlated relaxation and liquid crystal NMR spectroscopy.” in Journal of the American Chemical Society (132, 10866-10875, 2010).

In this paper a large amount of residual chemical shifts of amide 1H and its Chemical Shift Anisotropy (CSA)/Dipole-Dipole (DD) interaction cross-correlated relaxation rates were measured, from which a five dimensional amide 1H CSA tensor was accurately determined for each residue in rigid regions of the model protein GB3. The authors concluded that the variability of the 1H CSA tensor is rather large, primarily due to the variation of the hydrogen bond to 1H atom throughout the protein. An empirical equation was proposed to describe this relationship. The study also suggested that the 1H TROSY component has a substantial variation and the average optimum magnetic field is ~1200 MHz, for the narrowest linewidth in 1H dimension.

This work provides an opportunity to better understand the amide proton CSA, an important physical quantity in NMR. The advanced methods utilized and developed in the work can also be employed in other related research.