title: Synthesis of the disaccharide 6-O-beta-D-galactopyranosyl-2-acetamido-2-deoxy-D-galactose using immobilized beta-galactosidase.
abstract: The disaccharide 6-O-beta-D-galactopyranosyl-2-acetamido-2-deoxy-D-galactose has been synthesized by transfer of the beta-D-galactopyranosyl residue from lactose to 2-acetamido-2-deoxy-D-galactose utilizing the transferase activity of beta-galactosidase from E. coli. To make the enzyme reusable, it was applied in an immobilized form covalently bound to Sepharose CL-4B. The yield of the disaccharide was about 20%, calculated on the amount of acetamido-deoxy-D-galactose added. The disaccharide could also be obtained by reversal of the hydrolytic activity of the enzyme, using D-galactose and 2-acetamido-2-deoxy-D-galactose as substrate. The yield in this reaction, however, was only 2-3% under the conditions applied.
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004187:Disaccharides / Q000138:chemical synthesis*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D005696:Galactosidases / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D007202:Indicators and Reagents; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D004187:Disaccharides; D004800:Enzymes, Immobilized; D007202:Indicators and Reagents; C042701:6-O-galactopyranosyl-2-acetamido-2-deoxygalactose; D005696:Galactosidases; D001616:beta-Galactosidase