Agaricus bisporus (Mushroom) Lectin (ABA/ABL) – Pure
Agaricus bisporus agglutinin/lectin (ABA/ABL) is isolated from white button mushrooms. It has a molecular weight of 58, 500 as determined by gel filtration that corresponds to a tetramer, and has an isoelectric point that ranges between pH 5.0 and pH 6.0. ABA is a mixture of two phytohemagglutinins (PHA) with similar specificities for carbohydrate (PHA-A and PHA-B). Each monomer has 2 distinct carbohydrate binding sites, one for galactose–1, 3-N-acetylgalactosamine and another for galactose–1, 3-N-acetylglucosamine, but does not bind monosaccharides.ABA has a non-specific blood group recognition since PHA-A and PHA-B agglutinate erythrocytes independent of their blood group type. The O-linked glycopeptide released by trypsin is a potent inhibitor of both the isolectins. Removal of the terminal sialic acid residue from the glycopeptide increases its inhibitory potency by 8-fold. Periodate or -galactosidase treatment of the trypsin released glycopeptide destroys all inhibitory activity. Simple sugars are very poor inhibitors of these isolectins. However, a galactose residue appears to play a major role in these lectin binding mechanisms. The sugar linkage is also important since a synthetic N-linked glycopeptide is not inhibitory.ABA can be internalized by clathrin-coated vesicles after binding to surface glycoproteins. After internalization, it inhibits nuclear import of nuclear localization signal-dependent proteins. See other ABA conjugates.This product comes in lyophilized form and is stored below -20° C.