Bioactive proteins from marine sponges: screening of sponge extracts for hemagglutinating, hemolytic, ichthyotoxic and lethal properties and isolation and characterization of hemagglutinins.

Aqueous extracts of 48 sponge species from the Red Sea, the Australian Barrier Reef and the Florida Keys were screened for hemagglutinating, hemolytic, ichthyotoxic and lethal activities. Forty two per cent of the sponge species exhibited agglutinating properties to human erythrocytes of ABO groups. From four species (Haliclona sp., Cinachyra tenuifolia, Callyspongia viridis, Terpios zeteki) the hemagglutinating factors were isolated by gel filtration and affinity chromatography. A molecular weight of 24,000 was determined for the pure hemagglutinin from Haliclona sp. by SDS electrophoresis and of 22,000 for the semipure hemagglutinin from Cinachyra tenuifolia by gel filtration. These hemagglutinins were inhibited by D-lactose, but not by D-melibiose or other oligosaccharides, indicating that they may react with terminal D-galactose beta 1----4 residues. The other semipure hemagglutinins were not inhibited by various sugars tested. Hemolytic activity to human erythrocytes was present in about 15% of the sponge extracts, showing a close relationship to ichthyotoxic activity. More than half of the sponge extracts caused toxic symptoms in mice when injected i.p. Using various concentrations death occurred within 12-48 hr. The lethal factors seem to be related to components of low molecular weight in the sponge extracts.