We present the linear relation between backbone N-H bond effective rotational correlation times and R2 values as a new route to characterize protein and peptide dynamics experimentally. This is particularly promising approach for multi-domain proteins, IDPs and protein or peptides complexed with lipids or other biomolecules whose dynamics cannot be interpreted using standard approaches. We anticipate potential practical applications in a wide range of fields where such systems play significant roles. The presented approach can be used to investigate, for example, how drug binding affects dynamics of IDPs , rotation of peptides in lipid nanodiscs with potential pharmaceutical applications or dynamics of silk proteins forming novel materials . Furthermore, we provide a tool to immediately interpret the average rotational dynamics of residues of any kind of protein system from a spin relaxation experiment with only one magnetic field, contributing significant practical advance in the interpretation of NMR experiments in a wide range of fields.