THE STUDY OF INTRAMOLECULAR DYNAMICS BY NUCLEAR-MAGNETIC-RESONANCE

The possibilities of studying intramolecular dynamics by nuclear magnetic resonance are discussed. It is shown that processes on a very wide time scale, ranging from picoseconds to seconds and more, can be explored by NMR. The available techniques, their potential and their limitations are demonstrated by an application to the cyclic decapeptide antamanide. By rotating frame relaxation measurements, a slow torsional mode of the peptide backbone is investigated. The proline puckering motion can be studied by J-coupling and laboratory-frame relaxation measurements. Based on combined relaxation measurements the dynamics of the phenylalanine side chains with two motional degrees of freedom are characterized. The experimental results are compared with molecular dynamics simulation calculations.