Site-specific variations of carbonyl chemical shift anisotropies in proteins.

By combining molecular dynamics (MD) simulation with a novel extended density functional theory method, we calculate site-specific carbonyl chemical shift tensors in the SMN Tudor domain. We formulate a simple model for the C' chemical shift anisotropy (CSA) based solely on the isotropic chemical shift. Using this simple chemical shift tensor model and the MD simulation, an accurate prediction of transverse C'/N-H cross-correlated relaxation rates can be obtained.