Structural transformations in protein crystals caused by controlled dehydration

Thermodynamic and dynamic factors involved in the stability of native protein structure in amorphous solids in relation to levels of hydration

“…Alterations in the conformation of crystalline lysozyme during dehydration were observed by single-crystal X-ray diffraction. 264 Differences also were observed for the dehydrated crystal of form IX of bovine pancreatic RNase A, 265 which unlike most protein crystals, diffracts well when severely dehydrated. In these studies, greater displacements were observed for mainchain atoms in the dehydrated samples compared with those of the hydrated crystal, including large rearrangements and extensive disorder in the loop regions of the protein.…”

Data quality in area detector diffraction experiments

“…The structural determination of the HLA molecule by X-ray crystallography has provided valuable information for understanding how peptides bind to HLA. Originally, six pockets (A-F) were defined by calculating the surface of the binding groove based upon the crystal structure of HLA-A2 [1]. Since then, x-ray crystallography has been performed for a variety of HLA alleles bound to a range of peptides, which has lead to broader pocket definitions [2].…”

“…Among a variety of post-crystallisation treatments that have been described with the aim of improving crystal diffraction quality, crystal dehydration is one of the most successful one. Interestingly, dehydration may be accompanied by other remarkable changes, such as phase transitions [1], [2]. Phase transitions usually lead in a higher lattice symmetry, smaller cell volumes and reduced number of independent molecules in the asymmetric unit.…”