Crystallization, preliminary X-ray diffraction study, and crystal packing of a complex between anti-hen lysozyme antibody F9.13.7 and guinea-fowl lysozyme.

The complex formed between the Fab fragment of a murine monoclonal antihen egg lysozyme antibody F9.13.7 and the heterologous antigen Guinea-fowl egg lysozyme has been crystallized by the hanging drop technique. The crystals, which diffract X-rays to 3 A resolution, belong to the monoclinic space group P2(1), with a = 83.7 A, b = 195.5 A, c = 50.2 A, beta = 108.5 degrees and have two molecules of the complex in the asymmetric unit. The three-dimensional structure has been determined from a preliminary data set to 4 A using molecular replacement techniques. The lysozyme-Fab complexes are arranged with their long molecular axes approximately parallel to the crystallographic unique axis. Fab F9.13.7 binds an antigenic determinant that partially overlaps the epitope recognized by antilysozyme antibody HyHEL10.