CRYSTALS OF AN ANTIBODY F-V FRAGMENT AGAINST AN INTEGRAL MEMBRANE-PROTEIN DIFFRACTING TO 1.28 ANGSTROM RESOLUTION

The F-v fragment of a monoclonal antibody, 7E2 (IgG(1), kappa, murine) , which is directed against the integral membrane protein cytochrome c oxidase (EC 1.9.3.1) from Paracoccus denitrificans, was cloned and pr oduced in Escherichia coli. Crystals suitable for high-resolution X-ra y analysis were obtained by microdialysis under low salt conditions. T he crystals belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions of a b = 56.15 Angstrom, c = 99.86 Angstrom (1 An gstrom = 0.1 nm) and contain one F-v fragment per asymmetric unit. Usi ng synchrotron radiation diffraction data were collected up to 1.28 An gstrom resolution. This high resolution is very unusual for a heterodi meric protein. The crystals should open the way for refining not only the atomic positions, but also for obtaining information about interna l dynamics. (C) 1995 Wiley-Liss, Inc.