title: Preliminary crystallographic study of the Fab fragments of two monoclonal anti-2-phenyloxazolone antibodies.
abstract: We report on the preparation, crystallization, and preliminary x-ray crystallographic study of the Fab fragments of two monoclonal anti-2-phenyloxazolone antibodies obtained from the secondary response to this hapten. The Fab fragment from one of these (NQ10/12.5) has been crystallized from polyethylene glycol 8000 solutions in a form suitable for high-resolution x-ray crystallographic studies. These crystals are monoclinic, space group C2, with a = 129.2 A, b = 79.4 A, c = 57.7 A, beta = 96.2 degrees, and one Fab/asymmetric unit. Determination of the three-dimensional structure of Fab NQ10/12.5 should help clarify the role of somatic mutation in the maturation of an immune response. This antibody and an anti-lysozyme antibody also under study apparently use the same germ-line encoded VK and a similar VH gene, respectively, as the idiotypic anti-oxazolone antibodies characteristic of the primary response. A comparative study of the two structures should shed light on the role of the pairing of heavy and light chains in the antigen-binding function of antibodies.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D003460:Crystallization; D006241:Haptens; D007140:Immunoglobulin Fab Fragments / Q000302:isolation & purification; D051379:Mice; D010080:Oxazoles; D010081:Oxazolone / Q000031:analogs & derivatives; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D000911:Antibodies, Monoclonal; D006241:Haptens; D007140:Immunoglobulin Fab Fragments; D010080:Oxazoles; C018361:2-phenyloxazolone; D010081:Oxazolone