Collective NMR relaxation model applied to protein dynamics

A new dynamical model for the interpretation of nuclear magnetic resonance relaxation data is presented. It is based on a normal mode description, treating the low frequencies associated with collective motions as adjustable parameters to optimize agreement between calculated and experimental relaxation order parameters. This model provides a compact representation of many aspects of internal dynamics and characterizes motions affecting different spin pairs in a correlated way. Furthermore, it links together dynamical characteristics of different types of NMR observables and allows one to assess vibrational thermodynamic properties. Sample applications are given for a 25-residue zinc-finger peptide.