Crystallization and preliminary X-ray diffraction data of two heparin-binding fragments of human fibronectin.

Two different heparin-binding fragments of human fibronectin have been crystallized in forms which are suitable for crystal structure analyses. The 30 kDa hep-2A fragment, consisting of type III domains 12-14, was crystallized from solutions containing ammonium sulfate or polyethylene glycol 6000. The crystals grown in ammonium sulfate solutions were orthorhombic with space group I222 or I2(1)2(1)2(1) with a = 68.1 A, b = 88.6 A, and c = 144.9 A. The crystals grown in polyethylene glycol solutions are hexagonal with space group P6(1)22 or P6(5)22 with a = b = 66.7 A and c = 245.7 A. The 40 kDa hep-2B fragment, consisting of type III domains 12-15, was also crystallized from solutions containing ammonium sulfate with the addition of glycerol. Glycerol proved an effective agent for reducing the number of crystals in the crystallization experiments, and thus, increasing the size of the crystals in these experiments. This crystal form is nearly isomorphous to the orthorhombic form of the hep-2A fragment with space group I222 or I2(1)2(1)2(1) and a = 67.5 A, b = 87.0 A, and c = 144.3 A. All crystal forms diffract to at least 3.5 A resolution and contain a single molecule in the asymmetric unit.