Hemagglutinating activity and structural stability of a snail egg-protein

ITUARTE,S.; DREON, M.S.; HERAS, H.

Potrero de los Funes

Congreso; XLVII Reunión SAIByBM; 2011

SAIByBM

Many glycan binding proteins have been isolated from mollusks, where they function as recognition and immune molecules. Here we report the hemagglutinatig activity of scalarin (SC), an egg protein from the aquatic snail Pomacea scalaris, and characterize this activity in the context of the structural stability of the protein. Two biological functions, found in related proteins, were assayed: trypsin inhibition and hemaglutinating activity. Scalarin did not inhibit trypsin but showed high agglutinating activity against rabbit red cells. Hemagglutination was not altered by the presence of divalent cations and it was strongly inhibited by glucosamine, galactosamine and GalNAc. Scalarin can withstand/was resistant to pepsin and trypsin digestion. Temperature and pH stability, analyzed by fluorescence and visible spectroscopy, indicated that it was stable up to 60°C; in coincidence with a loss of hemaglutinating activity at this temperature. While SC did not show structural perturbations between pH 2.0 and 10.0, a loss in activity was observed below pH 4.0 and above pH 8.0. These results strongly suggest that Scalarin has the potential of becoming a biotechnologically useful agglutinin (lectin), due to its wide pH and temperature stability range and specificity. This is the first report of a protease-resistant glycan binding protein in a Pomacea snail, a genus where novel egg-defense systems were recently described.