title: Erythrocyte-binding studies on an acidic lectin from winged bean (Psophocarpus tetragonolobus).
abstract: An acidic lectin (WBA II) was isolated to homogeneity from the crude seed extract of the winged bean (Psophocarpus tetragonolobus) by affinity chromatography on lactosylaminoethyl-Bio-Gel. Binding of WBA II to human erythrocytes of type-A, -B and -O blood groups showed the presence of 10(5) receptors/cell, with high association constants (10(6)-10(8) M-1). Competitive binding studies with blood-group-specific lectins reveal that WBA II binds to H- and T-antigenic determinants on human erythrocytes. Affinity-chromatographic studies using A-, B-, H- and T-antigenic determinants coupled to an insoluble matrix confirm the specificity of WBA II towards H- and T-antigenic determinants. Inhibition of the binding of WBA II by various sugars show that N-acetylgalactosamine and T-antigenic disaccharide (Thomsen-Friedenreich antigen, Gal beta 1-3GalNAc) are the most potent mono- and di-saccharide inhibitors respectively. In addition, inhibition of the binding of WBA II to erythrocytes by dog intestine H-fucolipid prove that the lectin binds to H-antigenic determinant.
authors: UGC Centre for Advanced Studies, Indian Institute of Science, Bangalore.
authors: S R
authors: SR
authors: Patanjali
authors: S U
authors: SU
authors: Sajjan
authors: A
authors: A
authors: Surolia
mesh_terms: D001665:Binding Sites; D001789:Blood Group Antigens; D002241:Carbohydrates / Q000494:pharmacology; D002846:Chromatography, Affinity; D000939:Epitopes / Q000032:analysis; D004912:Erythrocytes / Q000276:immunology / Q000378:metabolism*; D007887:Fabaceae; D006801:Humans; D066298:In Vitro Techniques; D037102:Lectins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D037121:Plant Lectins; D010946:Plants, Medicinal; D011975:Receptors, Mitogen / Q000378:metabolism
chemical_list: D001789:Blood Group Antigens; D002241:Carbohydrates; D000939:Epitopes; D037102:Lectins; D037121:Plant Lectins; D011975:Receptors, Mitogen