Elastic and inelastic diffraction changes upon variation of the relative humidity environment of PurE crystals

The results observed for three different crystal forms of the enzyme PurE are reported and an attempt is made to infer some initial conclusions regarding the role that the solvent, the crystallization agents (mainly salts and polyethylene glycol) and interactions within the protein structures play in determining the changes in the diffraction pattern upon alteration of the external relative humidity of the crystals.