IDENTIFICATION OF A GLYCOPROTEIN LIGAND FOR E-SELECTIN ON MOUSE MYELOID CELLS

E-selectin is an inducible endothelial cell adhesion molecule for neut rophils which functions as a Ca2+-dependent lectin. Using a recombinan t, antibody-like form of mouse E-selectin, we have searched for glycop rotein ligands on mouse neutrophils and the neutrophil progenitor cell line 32D cl 3. We have identified a 150-kD glycoprotein as the only p rotein which could be affinity-isolated with soluble E-selectin from [ S-35]Methionine/[S-35]cysteine-labeled 32D cl 3 cells. Binding of this protein was strictly Ca2+-dependent, was blocked by a cell adhesion-b locking mAb against mouse E-selectin, and required the presence of sia lic acid on the 150-kD ligand. This glycoprotein was also affinity-iso lated from mature neutrophils, in addition to a minor component at 250 kD, but could not be isolated from several other non-myeloid cell lin es. The 150-kD glycoprotein was the only protein from 32D cl 3 cells, which was detectable by silver-staining after a one-step affinity-isol ation.