Hydrogen/deuterium exchange behavior in tetragonal hen egg-white lysozyme crystals affected by solution state

Neutron diffraction studies of hydrogen/deuterium-exchanged hen egg-white lysozyme were performed by a joint X-ray and neutron refinement to elucidate the hydrogen/deuterium exchange behavior. Large crystals for neutron work, consisting of molecules that were exchanged before crystallization, were obtained by repeatedly adding protein solution to the crystal batch using deuterated precipitant reagent. There are differences in hydrogen/deuterium exchange behavior compared with previous crystallographic or NMR studies, which could be due to intermolecular interactions in the crystal or to different lengths of exchange period.