regions. However, caution should be exercised as chemical exchange contributions may affect experimental R2 values. Chemical exchange contribution can be extracted from data measured with multiple magnetic fields in some cases, but its potential role may be difficult to observe from R2 values measured only with one magnetic field strength. Nevertheless, residues affected by the chemical exchange gave longer τ eff values when the specific correction term was not used (e.g. residues around 50 in Fig. a), indicating slower dynamics for these residues, which is qualitatively correct interpretation for the effect exhibiting chemical exchange to rotational dynamics.