CHARACTERIZATION OF CRYSTALS OF AN INTACT MONOCLONAL-ANTIBODY FOR CANINE LYMPHOMA

A monoclonal antibody of the subclass IgG2a specific for canine lymphoma cells has been crystallized by vapor diffusion from polyethylene glycol 8000. The crystals, which occasionally measure nearly a millimeter on edge, have been examined by X-ray diffraction. The crystals are of triclinic space group P1 with unit cell parameters of a = 66·39 A ̊, b = 77·34 A ̊, c = 101·42 A ̊, α = 87·60 °, β = 92·55 °, γ = 97·54 ° and cell volume of V = 4·84 × 105A ̊3. There is one entire antibody molecule as the asymmetric unit of the crystals. Three-dimensional X-ray diffraction data have been collected to 2·8 Å resolution and a self rotation function calculation shows a pronounced peak indicating at least an approximate non-crystallographic dyad axis. © 1991.