Multiglycosyltransferase System of Canine Respiratory Tissue

摘要: A galactosyltransferase has been found in a particulate preparation prepared from normal canine respiratory tissue which catalyzes the transfer of galactose its uridine diphosphate derivative to N-acetylgalactosamine residues. The sialidase-treated ovine submaxillary mucin was dependent upon Mn2+ and stimulated several-fold by Triton X-100. optimal pII between 6 7. Km 7 x 10-4 m for UDP-galactose 1 10-3 mucin. Removal residues on this acceptor reduced incorporation galactose. enzyme present throughout airway passage with some evidence higher activity lower portion trachea extrapulmonary primary bronchi. Fetuin sialic acid were removed also an (Km = 0.9 ). When terminal N-acetylglucosamine acceptor, reduced. No competition demonstrated when mixed mucin; suggests that there are at least two separate galactosyltransferases or catalytic sites same molecule.