Crystallization of the OP-G2 Fab fragment: a fibrinogen mimic with specificity for the platelet glycoprotein IIb/IIIa

The OP-G2 monoclonal antibody binds to the platelet integrin, gpIIb/IIIa, in a mode that mimics fibrinogen binding. The specificity of this antibody is mediated by the third complementarity-determining region (CDR3) loop of the immunoglobulin heavy chain which contains a sequence (RYD) related to the RGD recognition sequence of fibrinogen. The OP-G2 Fab fragment has been crystallized by vapor diffusion from solutions containing polyethylene glycol and imidazole malate (pH 5.6). The crystals belong to space group P2₁2₁2 with a = 93.1, b = 83.8 and c = 53.7 Å. One Fab molecule is present in the asymmetric unit. A complete data set to 2.0 Å resolution has been collected.