β-(1-4)-galactosidase

Non-reducing terminal β(1-4)-Galactose. The number of antennae does not affect cleavage rate. Fucose linked to the penultimate N-acetylglucosamine will block the cleavage of the galactose.

β Galactosidase from Streptococcus pneumoniae releases only β(1-4) linked, non-reducing terminal galactose from complex carbohydrates and glycoproteins. β(1-4) galactose is by far the most common linkage found in N-linked oligosaccharides. For other galactosidase linkages, β(1-3,4,6)-Galactosidase from Bovine testes is recommended. The enzyme is as active on tetraantennary oligosaccharides as on disaccharides containing β(1-4)-linked galactose. Fucose linked to the penultimate N-acetylglucosamine will block the cleavage of the galactose. Up to 100 µg of asialofetuin can be completely β(1-4)-degalactosylated in less than 1 hour using 3 mU of enzyme.