title: The B4 lectin from Vicia villosa seeds interacts with N-acetylgalactosamine residues on erythrocytes with blood group Cad specificity.
abstract: We have previously shown that the B4 lectin from Vicia villosa seeds interacts with N-acetylgalactosamine alpha-linked to serine or threonine in cell surface glycoproteins. In the present study, we show that the lectin also binds to Cad erythrocytes (0.44-2.78 X 10(6) sites/cell) with an association constant of 0.61-0.84 X 10(7)M-1. Variability in the number of B4 lectin binding sites in Cad erythrocytes from different individuals parallels reactivity of these erythrocytes with other N-acetylgalactosamine-binding lectins. Agglutination of Cad erythrocytes with B4 lectin is inhibited by urinary Tamm-Horsfall Sda-active glycoprotein. Since the Cad and Sda determinants share the terminal GalNAc beta 1.4----Gal sequence, our results indicate that Vicia villosa B4 lectin can also interact with terminal beta-linked N-acetylgalactosamine in closely-spaced oligosaccharide units of cell surface glycoproteins.
mesh_terms: D000116:Acetylgalactosamine / Q000097:blood*; D001789:Blood Group Antigens / Q000276:immunology*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004910:Erythrocyte Membrane / Q000276:immunology*; D005688:Galactosamine / Q000031:analogs & derivatives*; D006801:Humans; D007700:Kinetics; D037102:Lectins / Q000302:isolation & purification; D037121:Plant Lectins; D012639:Seeds / Q000032:analysis
chemical_list: D001789:Blood Group Antigens; D037102:Lectins; D037121:Plant Lectins; D005688:Galactosamine; D000116:Acetylgalactosamine