The specificity of sialytransferases using glycosylated lysozyme derivatives as substrates.
Galactose, lactose, N-acetylgalactosamine, N-acetylglucosamine and fibrinoglycopeptides were bound to lysozyme by different linkages. These glycosylated lysozymes were tested as N-acetylneuraminic acid acceptors using particular sialytransferase preparations from frog and bovine liver and from bovine and porcine submandibular glands. Desialylated fetuin served as reference compound. Galactose residues of desialo-fetuin and lysozyme-lactose are sialylated by all four sialytransferases tested, galactose bound to lysozyme via a phenylazo group is inactive with the enzyme from bovine submandibular gland, and galactose bound directly to lysozyme serves as substrate only for the frog liver sialytransferase. Lysozyme-phenylazo-N-acetylgalactosamine is active only with the sialytransferase from bovine sumbandibular gland. N-Acetylglucosamine derivatives of lysozyme are inactive with all sialytransferases tested. These observations are discussed in the light of the natural substrates for the sialytransferases investigated.
D006020:Glycopeptides; D007700:Kinetics; D009113:Muramidase; D011485:Protein Binding; D012799:Sialyltransferases / Q000378:metabolism*; D013379:Substrate Specificity; D014166:Transferases / Q000378:metabolism*
D006020:Glycopeptides; D014166:Transferases; D012799:Sialyltransferases; D009113:Muramidase