A sialic acid-specific lectin from the slug Limax flavus

The slug, Limax flavus, contains a lectin that appears to be highly specific for sialic acid residues of glycoproteins. The carbohydrates which inhibited the hemagglutinating activity of the slug lectin and the concentration of the carbohydrate which gave a 50% inhibition are as follows: N-acetylneuraminic acid, 0.13 mm; N-glycolylneuraminic acid, 0.90 mm; d-glucosamine, 4.9 mm; d-galactosamine, 7.6 mm; N-acetyl-d-glucosamine, 23 mm; and N-acetyl-d-galactosamine, 24 mm. d-Galactose, d-glucose, d-mannose, α-methyl-d-glucoside, α-methyl-d-mannoside, l-arabinose, d-xylose, l-fucose, d-glucuronic acid, lactose, and sucrose were found to be ineffective as inhibitors of the hemagglutinating activity of the slug lectin. Hemagglutination by slug lectin was strongly inhibited by bovine submaxillary mucin and fetuin but not by sialic acid-free bovine submaxillary mucin or fetuin.