Preliminary X-ray crystallographic analysis of Bowman-Birk trypsin inhibitor from barley seeds.

Bowman-Birk trypsin inhibitor from barley seeds has been crystallized at room temperature using polyethylene glycol as precipitant. The crystal is tetragonal, belonging to the space group P41212 (or P43212), with unit cell parameters of a = b = 62.48 and c = 94.63 A. The asymmetric unit contains one molecule of Bowman-Birk trypsin inhibitor with corresponding crystal volume per protein mass (Vm) of 2.89 A3 Da-1 and the solvent content of 57% by volume. The crystals diffract to at least 1.9 A Bragg spacing upon exposure to synchrotron X-rays. X-ray data to 1.9 A have been collected from a native crystal.