Crystallisation and preliminary X-ray analysis of the receptor-binding domain of human and bovine α2-macroglobulin

AbstractThe receptor-binding domains (RBDs) of human and bovine α2-macroglobulin (α2M) have been isolated after limited proteolysis of methylamine-treated α2M with papain. Single crystals of the RBDs have been grown by vapour diffusion. Crystals of human RBD are very thin plates unsuited for data collection. However, crystals of RBD from bovine α2M give diffraction patterns suitable for X-ray analysis, and a complete dataset with a maximum resolution of 2.3 Å has been collected with synchrotron radiation at cryogenic temperature. The crystals belong to spacegroup P3121 or P3221 with cell parameters a = b = 106.8 Å, c = 72.2 Å