title: alpha-(2,6)-Sialyltransferase-catalyzed sialylations of conformationally constrained oligosaccharides.
abstract: It is demonstrated that conformationally restricted oligosaccharides can act as acceptors for glycosyltransferases. Correlation of the conformational properties of N-acetyl lactosamine (Galbeta(1-4)GlcNAc, LacNAc) and several preorganized derivatives with the corresponding apparent kinetic parameters of rat liver alpha-(2,6)-sialyltransferase-catalyzed sialylations revealed that this enzyme recognizes LacNAc in a low energy conformation. Furthermore, small variations in the conformational properties of the acceptors resulted in large differences in catalytic efficiency. Collectively, our data suggest that preorganization of acceptors in conformations that are favorable for recognition by a transferase may improve catalytic efficiencies.
authors.affiliation: Complex Carbohydrate Research Center, University of Georgia, 220 Riverbend Road, Athens, Georgia 30602, USA.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Galan
authors.forename: Andre P
authors.initials: AP
authors.lastname: Venot
authors.forename: John
authors.initials: J
authors.lastname: Glushka
authors.forename: Anne
authors.initials: A
authors.lastname: Imberty
authors.forename: Geert-Jan
authors.initials: GJ
authors.lastname: Boons
mesh_terms: D000606:Amino Sugars / Q000737:chemistry* / Q000378:metabolism; D002236:Carbohydrate Conformation; D004187:Disaccharides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D012799:Sialyltransferases / Q000737:chemistry* / Q000378:metabolism; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
chemical_list: D000606:Amino Sugars; D004187:Disaccharides; C000458:N-acetyllactosamine; D012799:Sialyltransferases; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase