Multiple recognition systems adopting four different glycotopes at the same domain for the Agaricus bisporus agglutinin-glycan interactions.

For the GalNAcalpha1--> specific Agaricus bisporus agglutinin (ABA) from an edible mushroom, the mechanism of polyvalent Galbeta1-->3/4GlcNAcbeta1--> complex in ABA-carbohydrate recognition has not been well defined since Gal and GlcNAc are weak ligands. By enzyme-linked lectinosorbent and inhibition assays, we show that the polyvalent Galbeta1-->3/4GlcNAcbeta1--> in natural glycans also play vital roles in binding and we propose that four different intensities of glycotopes (Galbeta1-3GalNAcalpha1-, GalNAcalpha1-Ser/Thr and Galbeta1-3/4GlcNAcbeta1-) 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.