The basic phospholipase A2 from the venom of Agkistrodon halys pallas possesses the ability to cause hemolysis in contrast to the other two phospholipase A2 from the same venom. A new form of crystals of this enzyme was grown. The crystals belong to space group of P212121 with unit cell parameters of a=9. 175nm, b=10.080nm , c=2.287nm.The crystals diffract to high resolution, and are suitable for detailed structural studies. The data were collected up to 0.25nm resolutiorl using synchrotron radiation-imaging plate-Weissenberg camera system. Preliminary analysis reveals the presence of two molecules in the asymmetric uint and the molecule may pack with the smallest dimension approximately parallel to the c axis. The new crystal form is more attractive than the monoclinic one previously reported for crystallographic structure determination as it contains fewermolecules in the asymmetric unit.
