Receptors for Dolichos biflorus agglutinin on embryonal carcinoma cells

Dolichos biflorus agglutinin (DBA), a lectin specific for N-acetylgalactosamine residues, agglutinated F9 embryonal carcinoma cells. FITC-labeled DBA intensively stained F9 cells, and embryonal carcinoma cells and endodermal cells of teratocarcinoma OTT6050, but did not stain a variety of cells from the host (129 mouse). Receptors for DBA were isolated from galactose-labeled F9 and OTT6050 cells by solubilization with 0.5% Triton X-100 and affinity chromatography on DBA-agarose. About 40% of the non-dialyzable galactose-label in the extracts of both types of cells was recovered in the receptors. On SDS gel electrophoresis, most of the receptors behaved as glycoproteins with molecular weights of more than 70,000. The receptors from OTT6050 cells contained about 0.8 mg of carbohydrate per mg protein. Pronase digestion depolymerized the receptors from F9 and OTT6050 cells, but most of the resulting glycopeptides were still large enough to be excluded from a column of Sephadex G-50.