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.

Localized agglutinin staining in muscle capillaries from normal and very old atrophic human muscle using winged bean ( Psophocarpus tetragonolobus ) lectin

“…The basic lectins agglutinate human type A and B but not human type 0 trypsinized erythrocytes (Kortt 1984). The acidic lectins agglutinate trypsinized and desialized erythrocytes of all three (A, B, and 0) types (Kortt 1985;Patanjali et al 1988). According to Khan et al (1986), GalNAc is a better inhibitor than galactose for both groups of lectins, although the specificity of the basic lectins seems to be directed toward α-galactosides and the specificity of the acidic lectins toward β-galactosides.…”

Molecular recognition XIII. The binding of the H-type 2 human blood group determinant by a winged bean (Psophocarpus tetragonolobus) acidic lectin

“…The isolation of the winged bean acidic lectin was carried out as described recently (2). The thermodynamic parameters were determined by fluorescence substitution titration at three different temperatures, as described previously (3).…”

“…Accordingly, it was concluded that the lectins may recognize a complex carbohydrate determinant not represented by the sugar structures that were examined (I). More recently (2), affinity chromatography provided an electrophoretically homogeneous preparation, termed WBA 11, which was found to possess an affinity for a dog-intestine H-fucolipid. Indeed, it was subsequently shown (3) that the affinity for 2'-fucosyllactose (a-L-Fuc-(1 + 2)-P-D-Gal-(1 + 4)qP-DGlc) is 13 times greater than that for the H-disaccharide (a-L-'For the previous publication in this series, see ref.…”

“…3~niversity of Alberta Postdoctoral Fellow, 1992-1993. 4~esearch Associate, 1984-1988, 1991-1993 Fuc-(1 + 2)-a,P-D-Gal). Since the 2'-fucosyllactose is bound 14 times more strongly than an H (type 1)-related pentasaccharide (a-L-Fuc(1 + 2)-P-D-GalL(1 + 3)-P-D-GlcNAc-(1 + 3)-P-D-Gal-(1 + 4)-a,P-D-Glc), it was anticipated that WBA I1 would have a strong affinity for the H-type 2 blood group-deter-…”

Lectinomics I. Relevance of exogenous plant lectins in biomedical diagnostics

“…The UEA-I lectin was used for detection of the H-substance and determination of secretor status (Rahat et al 1990). Competitive hemagglutination studies with blood-groupspecific lectins reveal that WBA II lectin binds to H-and T-antigenic determinants on human erythrocytes (Patanjali et al 1988). The binding specificities of ABO blood group-recognizing lectins were studied using numerous techniques including lectin-blotting analysis, enzyme linked immunosorbent assay and lectinconjugated agarose column chromatography (Matsui et al 2001).…”