Dislocations in high-quality glucose isomerase crystals grown from seed crystals

Glucose isomerase crystals with thicknesses of 0.5 mm were grown using seed crystals. The thickness required for better X-ray topographic images by kinematical theory is determined by the extinction distance, _g. The seed crystals were cross-linked with glutaraldehyde to maintain stability for a long period before the growth experiments. Dislocations that were produced during the growth of such thick glucose isomerase crystals were observed as clearly as those in inorganic crystals via X-ray topography with monochromatic-beam synchrotron radiation, which is attributed to the high quality of the glucose isomerase crystals. This also indicates that high-quality protein crystals can be grown using seed crystals. The dislocations extended from the interface with the cross-linked seed crystal to the surface of the grown crystal; however, no dislocations were generated if the seed crystal was not cross-linked. We discuss the effect of the chemical cross-linking of the seed on the generation of dislocations from seed crystals.