Crystals of crotoxin suitable for high resolution x-ray diffraction analysis

Abstract

The phospholipasic presynaptic neurotoxin, crotoxin, has been crystallized in a morphology suitable for single crystal x-ray diffraction analysis. The conditions for growth and the unit cell parameters (P4(1)22 or P4(3)22, a = b = 38.5 A, c = 256.9 A, 1 molecule/asymmetric unit) are similar to the very thin plate-like crystals which have been studied with electron diffraction and electron microscopy by Chiu and his colleagues (Jeng, T.-W., Chiu, W., Zemlin, F., and Zeitler, E. (1984) J. Mol. Biol. 175, 93 - 97). These two macroscopic crystal morphologies of what is likely to be a very similar, if not identical, lattice structure will permit the complementary application of electron diffraction/microscopy and x-ray diffraction to understanding the structural basis of the interactions between a phospholipasic neurotoxin and its membrane target.