Endogenous lectins of bovine pancreas

Affinity chromatography of salt and detergent extracts from bovine pancreas on glycosylated or glycoprotein-linked Sepharose 4B resulted in purification of different carbohydrate-binding proteins. Three species of proteins with molecular masses of 16 kDa, 35 kDa and 64 kDa exhibiting specificity for beta-galactosides, but none with preferential specificity for alpha-galactosides, were isolated from salt and detergent extracts. No Ca2+ was required for binding. Mannan-binding proteins of 37 kDa, 47 kDa and 94 kDa without Ca2+-requirement were only found in the salt extract. No other mannan-binding activity could be detected. Fucose-binding proteins of 34 kDa, 62 kDa and 70 kDa exhibiting Ca2+-requirement for binding were present in the salt extract and two proteins with 62 kDa and 70 kDa in detergent extract. The different fractions showed agglutination activity when assayed with rabbit erythrocytes. Thus they can be defined as lectins.