CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION STUDIES OF THE SOLUBLE 14-KDA BETA-GALACTOSIDE-BINDING LECTIN FROM BOVINE HEART

The soluble 14 kDa β-galactoside-binding lectin from bovine heart, a member of the S-type lectin family, has been crystallized in a form suitable for X-ray diffraction analysis. The crystals, in the absence of a saccharide ligand, diffract beyond 2.5 å resolution. They are obtained from polyethylene glycol 6000 at pH 6.0. Crystals grow as monoclinic plates, space group P21, with cell dimensions: a = 35.47 å, b = 64.33 å, c = 58.78 å and β = 91.7°. The asymmetric unit contains two molecules related by a 2- fold non-crystallographic axis. Two lectin monomers in the asymmetric unit give a V(m) of 2.4 å3/Da, i.e. a solvent content of approximately 50%. The complex of lectin with the saccharide ligand, N-acetyllactosamine, crystallizes in the space group P21212 with cell dimensions: a = 63.55 å, b = 82.13 å and c = 62.39 å. Crystals of this complex diffract beyond 2.0 å resolution. Two complexes in the asymmetric unit lead to a V(m) value of 2.8 å3/Da (57% solvent). © 1994 Academic Press Limited.