Crystallization and preliminary X-ray data of proteins derived from prothrombin

Crystals of bovine prothrombin fragment 1 and deglycosylated fragment 1 have been grown from polyethylene glycol, Tris-maleate solutions and the crystals scatter x-rays at 2.8 Å resolution. The crystals of both are tetragonal, space group P4₁2₁2, or P4₃2₁2, with 1 molecule per asymmetric unit. Moreover, the two appear to be isomorphous. Since the mother liquor can support Ca²⁺ ion without precipitation, crystals have been soaked with Ca²⁺ ion and preliminary results indicate that these remain closely isomorphous with parent crystals. Isomorphous heavy atom derivatives of mercury and platinum have been prepared of glycosylated fragment 1. In addition, crystals of human prothrombin fragment 1 have also been grown.