A simple approach to deriving motional dynamics information of protein and peptide side chains by using 13 C NMR relaxation data is presented. By using linear approximation of internal rotational correlation functions, simple equations for relating side-chain conformation, bond rotational amplitudes, and rotational correlation coefficients with different NMR relaxation parameters have been obtained. Auto- and cross-correlation spectral densities are considered, and it is shown that proton-coupled 13 C NMR relaxation measurements allow detailed motional information to be obtained.
Bibliographical noteFunding Information:
This work was supported by research grants from the National Science Foundation (MCB-9729539), the National Institutes of Health (AA-10806), and the North Atlantic Treaty Organization (CRG-970039).