Dynamics in the p38α MAP Kinase–SB203580 Complex Observed by Liquid‐State NMR Spectroscopy

Added flexibility: NMR data for p38α MAP kinase in a complex with the SB203580 inhibitor show intermediate exchange of residues in the binding pocket (affected residues marked in blue and red on the structure), which indicates increased flexibility compared to that of the unbound protein. Based on residual dipolar couplings, the overall solution structure of p38α is very similar to the crystal structure. Thus, the increased mobility in solution is an effect of the inhibitor that is not reflected in the crystal structure.