Rotating frame spin‐lattice relaxation experiments and the problem of intramolecular motions of peptides in solution

The application of rotating frame spin‐lattice relaxtion to the determination of the intramolecular motions in peptides is discussed, and results are presented on the application of 13C T1p to peptide microdynamics in solution. The effective molecular rotational reorientation times at the amide and amino nitrogens may be derived from appropriate data onT1p of the carbons adjacent to them. We also show by theoretical caculations that 1H and 13C T1p experiments of suitable 2H and 15N substituted peptides will allow intramolecular main‐ and sidechain motions, characterized by times in the range 10−1–10−6 sec, to be investigated.