Rapid purification of collagen binding glycoproteins secreted by cultured endothelial cells

Two distinct lines of bovine aortal endothelial cells and also chick embryo fibroblasts, secrete two major non-associating collagen binding proteins into the growth medium. Both proteins are anionic, mannose-containing glycoproteins but differ in molecular weight (Mr = 220,000 and 70,000 daltons respectively), affinity for heparin and reactivity to antiserum against plasma fibronectin. The large molecular weight glycoprotein was identified as fibronectin. In this paper we present a novel rapid procedure for purification of each glycoprotein under non-denaturing conditions. A simple two step affinity column procedure was used to achieve high yields (80% and 85% respectively) of native, non-denatured glycoproteins suitable for fine analytical purposes and cell interaction studies.