Reactivity of Lectin from Xenopus laevis Eggs towards Tumor Cells and Human Erythrocytes

抄録

Lectin from eggs of Xenopus laevis showed strong agglutination of various tumor cells such as Ehrlich ascites cells and Sarcoma 180 ascites cells. Agglutination of human erythrocytes by the lectin occurs only after digestion of these cells by sialidase. Since lectin-induced cell agglutination was inhibited by D-galactose (the most effective monosaccharide inhibitor), and since the inhibitory activity of lacto-N-biose I was much higher than that of N-acetyllactosamine, the lectin seems to recognize the terminal D-galactosyl residues and particularly 3-O-β-D-linked oligosaccharide chains involving the Gal-GlcNAc-X-sequence. Trypsin or pronase treatment of sialidasetreated human erythrocytes converted them from an agglutinable to a nonagglutinable form. This result demonstrates that the lectin receptor site (s) exists in trypsin-labile cell surface glycoprotein (s).