CRYSTALLIZATION AND PRELIMINARY-X-RAY CRYSTALLOGRAPHIC ANALYSIS OF PROBABLE AMYLASE PROTEASE INHIBITOR-B FROM RICE SEEDS

Large crystals of probable amylase/protease inhibitor-B have been grown at room temperature from ammonium sulfate solution. The crystals grow within five days to dimensions of 0.6 mm x 0.6 mm x 0.6 mm. They diffract to at least 1.7 AÅ upon exposure to synchrotron X-rays. The crystals belong to the space group P41212 (or P43212) with unit cell dimensions of a = 38.02 AÅ and c = 98.98 AÅ. The presence of one molecule per asymmetric unit gives the unit cell volume per protein mass (Vm) of 1.99 AÅ3/Da and the solvent fraction of 38.2% by volume. X-ray data have been collected to 2.0 AÅ Bragg spacing from native crystals. © 1993 Academic Press, Inc.