Nature Chemistry, Published online: 10 June 2026; doi:10.1038/s41557-026-02155-0The extent to which crystal packing constrains protein dynamics is hard to decipher. Now a combination of NMR, crystallography and molecular dynamics simulations show that intermolecular contacts can slow ring flips down in crystals or accelerated them in complexes. A thermodynamic and structural analysis provides insights into the origins of the elevated free-energy barrier in crystals.
