Bandeiraea (Griffonia) simplicifolia lectin-I, isolectin A(4)(GS I-A(4
)) reacting with the Tn(GalNAc alpha 1 --> Ser/Thr) sequence or human
blood group P-k active disaccharide (E, Gal alpha 1 --> 4Gal, galabios
e) was studied by quantitative precipitin (QPA) and precipitin-inhibit
ion assays. When human blood group P-1 or Tn active glycoproteins were
tested by QPA, GS I-A(4) reacted strongly with both the Tn active gly
coproteins purified from asialo porcine, ovine and armadillo submandib
ular glands and a P-1 active glycoprotein isolated from sheep hydatid
fluid. They precipitated over 80% of the lectin nitrogen added, The as
ialo porcine salivary glycoprotein-GS I-A(4) interaction was inhibited
by both Tn containing glycopeptides and Gal alpha 1 --> 4Gal indicati
ng that GS I-A(4) not only reacts with human blood group A(GalNAc alph
a 1 --> 3Gal) and B(Gal alpha 1 --> 3Gal) active disaccharides, but al
so recognizes the Tn sequence and the E(Gal alpha 1 --> 4Gal) ligand,
From these results, the carbohydrate specificity of GS I-A(4) can be d
efined as A, Tn greater than or equal to B and E.