Three Recognition Mechanisms for Agaricus bisporus Agglutinin– Glycan Interactions

For the GalNAcα1→ specific Agaricus bisporus agglutinin (ABA) from an edible mushroom, the mechanism of polyvalent Galb1 → 3/4GlcNAcb1→ complex in ABA–carbohydrate recognition has not been well defined since Gal and GlcNAc were weak ligands. By enzyme-linked lectinosorbent and inhibition assays, it is shown the polyvalent Galb1 → 3/4GlcNAcb1→ in natural glycans also play vital roles in binding and proposed that four different intensities of glycotopes (Galb1-3GalNAcα1-, GalNAcα1-Ser/Thr and Galb1-3/4GlcNAcb1-) construct three recognition systems at the same domain. This peculiar concept provides the most comprehensive mechanism for the attachment of ABA to target glycans and malignant cells at the molecular level.