Bandeiraea (Griffonia) simplicifolia lectin-I, isolectin A4, reacting with Tn (Ga1NAc alpha1 --> Ser/Thr) or galabiose (Ga1 alpha1 --> 4Ga1) containing ligands.

Bandeiraea (Griffonia) simplicifolia lectin-I, isolectin A4(GS I-A4) reacting with the Tn(GalNAc alpha1 --> Ser/Thr) sequence or human blood group Pk active disaccharide (E, Gal alpha1 --> 4Gal, galabiose) was studied by quantitative precipitin (QPA) and precipitin-inhibition assays. When human blood group P1 or Tn active glycoproteins were tested by QPA, GS I-A4 reacted strongly with both the Tn active glycoproteins purified from asialo porcine, ovine and armadillo submandibular glands and a P1 active glycoprotein isolated from sheep hydatid fluid. They precipitated over 80% of the lectin nitrogen added. The asialo porcine salivary glycoprotein-GS I-A4 interaction was inhibited by both Tn containing glycopeptides and Gal alpha1 --> 4Gal indicating that GS I-A4 not only reacts with human blood group A(GalNAc alpha1 --> 3Gal) and B(Gal alpha1 --> 3Gal) active disaccharides, but also recognizes the Tn sequence and the E(Gal alpha1 --> 4-Gal) ligand. From these results, the carbohydrate specificity of GS I-A4 can be defined as A, Tn > or = B and E.