CODING AND CLASSIFICATION OF D-GALACTOSE, N-ACETYL-D-GALACTOSAMINE, AND BETA-D-GALP-[1-]3(4)]-BETA-D-GLCPNAC, SPECIFICITIES OF APPLIED LECTINS

Grouping of lectin-binding properties, based on determinant structure rather than monosaccharide-inhibition pattern, should facilitate the selection of lectins as structural probes for glycans, as well as for the interpretation of the distribution and the properties of the carbohydrate chains on the cell surface. Based on the binding specificities studied with glycan by precipitin-inhibition, competitive-binding, and hemagglutinin-inhibition assays, twenty D-galactose-or N-acetyl-D-galactosamine-(or both)-specific lectins have been divided into six classes according to their specificity for a disaccharide unit, as all or part of the determinants, and the alpha-D-GalpNAc-(1 --> 3)-Ser(Thr) unit of the glycopeptide chain. A scheme of classification is shown as follows: (a) F-specific lectins [alpha-D-GalpNAc-(1 --> 3)-D-GalNAc, Forssman specific disaccharide]: Dolichos biflorus (DBL), Helix pomatia (HPL), hog peanut (ABL, Amphicarpaea bracteata), and Wistaria floribunda (WFL) lectins. (b) A-specific lectins [alpha-D-GalpNAc-(1 --> 3)-D-Gal blood group A-specific disaccharide]: Griffonia (Bandeiraea) simplicifolia-A4 (GSI-A4), lima bean (LBL), soy bean (SBL), Vicia villosa (VVL), Wistaria floribunda (WFL), Dolichos biflorus (DBL), and Helix pomatia (HPL) lectins. (c) Tn-specific lectins [alpha-D-GalpNAc-(1 --> 3)-Ser(Thr) of the protein core]: Vicia villosa B4 (VVL-B4), Salvia sclarea (SSL), Maclura pomifera (MPL), Bauhinia purpurea alba (BPL), HPL, and WFL, lectins. (d) T-specific lectins [beta-D-Galp-(1 --> 3)-D-GalNAc, the mucin-type sugar sequences on human erythrocyte membrane and T antigen, or the terminal, nonreducing disaccharide end-groups of the gangliosides]: Peanut (PNA), Bauhinia purpurea alba (BPL), Maclura pomifera (MPL), Sophora japonica (SJL), Artocarpus integrifolia (Jacalin, AIL), and Artocarpus lakoocha (Artocarpin) lectins. (e) Type I and II specific lectins [beta-D-Galp-(1 --> 3 or 4)-D-GlCNAc, the disaccharide residues at the nonreducing end of the carbohydrate chains derived from either N- or O-glycans]: Ricinus communis agglutinin (RCA1), Datura stramonium (TAL, Thorn apple), Erythrina cristagalli (ECL,Coral tree), and Geodia cydonium (GCL), lectins. (f) B-specific lectin [alpha-D-Galp-(1 --> 3)-beta-D-Galp, human blood group B-specific disaccharide]: Griffonia (Bandeiraea) simplicifolia B4 (GSI-B4) lectin. Many other GalNAc- or Gal-(or both)-specific lectins that can be used as tools are also described.