Biochemical properties of hemagglutinins in the mollusk Pomacea flagellata

Extracts of the Mollusk Pomacea flagellata were found to contain two agglutinins (PFA-I and PFA-II) which reacted with erythrocytes from human and several animal species. The hemagglutinating activity was stable between pH 4.0 and pH 10.0, and was independent of divalent cations. The active components were purified and found to be glycoproteins having Mr of 30,000. The isoelectric points were estimated to be 4.7 and 4.9 for PFA-I and PFA-II respectively. Hapten inhibition assays indicated that the agglutinin and its isoforms are specific for β-galactosides as well as for galactose containing glycoproteins.