CORE ALPHA-1,3-FUCOSE IS A KEY PART OF THE EPITOPE RECOGNIZED BY ANTIBODIES REACTING AGAINST PLANT N-LINKED OLIGOSACCHARIDES AND IS PRESENTIN A WIDE VARIETY OF PLANT-EXTRACTS

Carbohydrates have been suggested to account for some IgE cross-reacti ons between various plant, insect, and mollusk extracts, while some Ig C antibodies have been successfully raised against plant glycoproteins . A rat monoclonal antibody raised against elderberry abscission tissu e (YZ1/12.23) and rabbit polyclonal antiserum against horseradish pero xidase were screened for reactivity in enzyme-linked immunosorbent ass ay against a range of plant glycoproteins and extracts as well as neog lycoproteins, bee venom phospholipase, and several animal glycoprotein s. Of the oligosaccharides tested, Man(3)Xyl-FucGlcNAc(2) (MMXF3) deri ved from horseradish peroxidase was the most potent inhibitor of the r eactivity of both YZ1/2.,23 and anti-horseradish peroxidase to native horseradish peroxidase glycoprotein, The reactivity of YZ1/2.23 and an ti-horseradish peroxidase against Sophora japonica lectin was most inh ibited by a neoglycoconjugate of bromelain glycopeptide cross-linked t o bovine serum albumin, while the defucosylated form of this conjugate was inactive as an inhibitor, A wide range of plant extracts was foun d to react against YZ1/2.23 and anti-horseradish peroxidase, with part icularly high reactivities recorded for grass pollen and nut extracts, All these reactivities were inhibitable with the bromelain glycopepti de/bovine serum albumin conjugate, Bee venom phospholipase and whole b ee venom reacted weakly with YZ1/2.23 but more strongly with anti-hors eradish peroxidase in a manner inhibitable with the bromelain glycopep tide/bovine serum albumin conjugate, while hemocyanin from Helix pomat ia reacted poorly with YZ1/2.23 but did react with anti-horseradish pe roxidase, It is concluded that the alpha 13-fucose residue linked to t he chitobiose core of plant glycoproteins is the most important residu e in the epitope recognized by the two antibodies studied, but that th e polyclonal anti-horseradish peroxidase antiserum also contains antib ody populations that recognize the xylose linked to the core mannose o f many plant and gastropod N-linked oligosaccharides.