Partial isolation and characterisation of a hemagglutinating factor from avocado seed.

Extracts of ground avocado seeds (Fuerte and Hass varieties), prepared in different buffer solutions (pH 2.0-12.0), show hemagglutinating activity towards A, B, AB, and H (0) human erythrocytes. The extract showing the highest titer of aggulination was extracted at pH 10.5. The crude extract also causes hemolysis of fresh washed erythrocytes. The hemagglutinating factor is not inhibited by most of the simple sugars tested, e.g., D-glucose, D-mannose, D-galactose, and glucose-amine. The only sugars which show some inhibitory effect are N-Acetyl-neuraminic acid, melibiose, and stachiose. Basic amino acids, e.g., lysine and arginine also inhibit its activity. However the most potent inhibitors of the agglutinin are proteins and glycoproteins such as bovine serum albumin, collagen, thyroglobulin, ovalbumin, mucin, and fetuin. The agglutinin is adsorbed on polymer beads such as Sepharose 4B, Sephadex G100, Agarose, and Chitin, and it reacts with hog erythrocyte membranes. It can be partially eluted from those materials with alkaline buffers (pH 9.0-10.5).