Bandeiraea (Griffonia) simplicifolia lectin‐I, isolectin A4, reacting with Tn (GalNAαl → Ser/Thr or galabiose (Galα1 → 4Gal) containing ligands

Abstract Bandeiraea (Griffonia) simplicifolia lectin-I, isolectin A 4 (GS I-A 4 ) reacting with the Tn(GalNAc α 1 → Ser/Thr) sequence or human blood group P k active dissacharide (E, Gal α 1 → 4Gal, galabiose) was studied by quantitative precipitin (QPA) and precipitin-inhibition assays. When human blood group P 1 or Tn active glycoproteins were tested by QPA, GS IA 4 reacted strongly with both the Tn active glycoproteins purified from asialo porcine, ovine and armadillo submandibular glands and a P 1 active glycoprotein isolated from sheep hydatid fluid. They precipitated over 80% of the lectin nitrogen added. The asialo porcine salivary glycoprotein-GS I-A 4 interaction was inhibited by both Tn containing glycopeptides and Gal α 1 → 4Gal indicating that GS I-A 4 not only reacts with human blood group A(GalNAc α 1 → 3Gal) and B(Gal α 1 → 3Gal) active dissacharides, but also recognizes the Tn sequence and the E(Gal α 1 → 4Gal) ligand. From these results, the carbohydrate specificity of GS I-A 4 can be defined as A, Tn ≥ B and E.