Crystallization of the Fab fragment of the tumour-specific antibody PR1A3

PR1A3 antibody binds specifically to the tumour-associated cell-surface antigen, carcinoembryonic antigen. Crystals of the Fab fragment of the PR1A3 antibody were obtained by vapour diffusion against mother liquor containing Tris-HC1 buffer, pH 8.6, magnesium chloride and polyethylene glycol 4000 as precipitating agent. Crystals belong to the monoclinic space group P2(1) with cell dimensions a = 42.2, b = 216.7, c = 45.9 A and beta = 95.6 degrees. Two Fab fragments are proesent in the asymmetric unit. Diffracted intensities up to 2.9 A resolution have been measured from frozen crystals.