Abstract
Protein single crystals of diffraction quality should be prepared for determination of three dimensional structure of whole protein molecule by X-ray crystallography. Microgravity environment obtained by space flights using space shuttle and space station has been ascertained to be convenient for protein crystallization since the first experiment by Littke in 1983. In space microgravity, there are no sedimentation and no convection of prtein and solute molecules in the solution. Also, crystal growth slowly proceeds by diffusion control nearby where crystal nuclei grew. Several times of our space experiments regarding protein crystallization are explained, and the space-grown crystals are emphasized to be of better difrraction quality and of less mosaicity. It is, therefore, expected that these characteristics of the space-grown crystals will contribute to the establishment of the time-resolved X-ray crystallograpy by the Laue method.
