title: Isolation and characterization of Rana catesbeiana lectin and demonstration of the lectin-binding glycoprotein of rodent and human tumor cell membranes.
abstract: A lectin isolated from Rana catesbeiana eggs preferentially agglutinates a large variety of human and animal tumor cells but not normal red blood cells, lymphocytes, or fibroblasts. The phenomenon correlates with a higher binding activity of the lectin with tumor cells. Chemical and physical analysis of the purified lectin indicates that the lectin is a low molecular weight basic polypeptide with five intrachain disulfide bonds. Its agglutination of tumor cells was abolished by blocking the amino group. The lectin strongly binds with a large variety of tumor cells but binds only minimally with fibroblasts, lymphocytes, and erythrocytes. Tumor cell agglutination induced by this lectin was strongly inhibited by submaxillary mucin, to a lesser degree by fetuin and keratan sulfate, and not at all by less-sialylated glycoproteins, such as transferrin. Inhibition by mucin or fetuin was greatly reduced by desialylation of glycoprotein with sialidase. Treatment of tumor cells with sialidase greatly reduced the lectin-dependent agglutination, and the sialidase-dependent reduction of tumor cell agglutination was inhibited by the sialidase inhibitor 2,3-dehydro-2-deoxy-N-acetylneuraminic acid. However, tumor cell agglutination was not inhibited by chondroitin sulfates or hyaluronic acid. Thus, the lectin-dependent tumor cell agglutination is due to a high density of sialic acid at the cell surface. The receptor glycoprotein that interacts with this lectin was demonstrated in the detergent-insoluble fraction of a variety of tumor cells by sodium dodecyl sulfate:polyacrylamide gel electrophoresis, followed by Western blotting with lectin and anti-lectin antibodies. The presence of a common high molecular weight lectin-binding glycoprotein in various tumor cells was demonstrated.
mesh_terms: D000371:Agglutination; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002460:Cell Line; D006023:Glycoproteins / Q000032:analysis* / Q000494:pharmacology; D006801:Humans; D037102:Lectins / Q000032:analysis / Q000302:isolation & purification*; D008565:Membrane Proteins / Q000032:analysis*; D008968:Molecular Conformation; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000032:analysis*; D009439:Neuraminidase / Q000494:pharmacology; D009844:Oligosaccharides / Q000494:pharmacology; D011892:Rana catesbeiana; D051381:Rats; D011975:Receptors, Mitogen / Q000032:analysis*
chemical_list: D000596:Amino Acids; D006023:Glycoproteins; D037102:Lectins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009844:Oligosaccharides; D011975:Receptors, Mitogen; D009439:Neuraminidase