Crystallization and preliminary X‐ray crystallographic analysis of chitinase from barley seeds

Chitinase from barley seeds has been crystallized at room temperature using polyethylene glycol as precipitant. The crystal is monoclinic, belonging to the space group P 2 1 , with unit cell parameters of a = 69.43 Å, b = 44.55 Å, c = 81.41 Å, and β = 111.95 Å. The asymmetric unit seems to contain two molecules of chitinase with a corresponding crystal volume per protein mass ( V M ) of 2.25 Å 3 /Da and a solvent content of 45% by volume. The crystal diffracts to at least 2.0 Å with X‐rays from a rotating anode source and is very stable in the X‐ray beam. X‐ray data have been collected to better than 2.2 Å Bragg spacing from a native crystal. © 1993 Wiley‐Liss, Inc.