Crystallization under microgravity of acidic phospholipase A2 from venom of Agkistrodon halys Pallas

Abstract A series of space crystallization experiments of an acidic phospholipase A 2 from venom of Agkistrodon halys Pallas were performed in August 1992 and in July 1994. On both missions, compared with earth-grown crystals in control experiments, space-grown crystals were larger, had fewer nuclei, and exhibited better habit. Significant improvements in crystal quality were achieved on 1994's mission, and the space-grown crystals exhibited stronger diffraction patterns and diffracted X-rays to high resolutions. Relative Wilson plots indicated that the space-grown crystals had higher internal order than the best laboratory-grown crystal. In addition, the results of the two space experiments suggested that the optimization of the space crystallization conditions, especially when an unconventional crystal growth method is engaged, plays an important role in exploiting microgravity more efficiently.