Fig. shows the water 1 H relaxometry profiles of the catalytic subunit of the cAMP-dependent protein kinase A (PKA), L-asparaginase II (ANSII), α7α7 proteasome solutions, and bovine serum albumin (BSA), at 298 K. The protein PKA, with a MW of 43.5 kDa, is expected to have a reorientation time of ca. 26 ns, as it can be estimated with HYDRONMR. The analysis of the relaxation profile actually shows contributions from correlation times of 28 ns (30%) and 5 ns (70%), with a very small contribution (0.4%) from a much longer correlation time of 240 ns which may point out to the presence of some aggregated form. The large contribution from the short correlation time indicates the relevance of the extensive fast local mobility for relaxation. The profiles of asparaginase can also be fitted with two correlation times, equal to 60 ns (42%) and 9 ns (58% The fit performed with Eq. ( ) and the contributions from the different correlation times are shown in the left panels of Fig. .