A NEW SURVEY OF BRAZILIAN MARINE-ALGAE FOR AGGLUTININS

Aqueous protein extracts from 30 Brazilian marine algae were examined for haemagglutinating activity using native and enzyme-treated rabbit, chicken, sheep and human erythrocytes. Most extracts agglutinated at least one of the blood cells used. Sheep and rabbit erythrocytes were more suitable for detection of the agglutinating activity. The minimum protein concentration necessary to produce positive agglutination was usually lower with enzyme-treated erythrocytes than native ones. The five algal protein extracts showing the greatest haemagglutination tit re were tested for sugar-binding specificity. Only the activity presen t in the green alga Caulerpa cupressoides was inhibited by simple suga rs and not by the glycoproteins tested. The activity of the other four extracts was inhibited by at least one of the glycoproteins utilised.