Chemoenzymatic synthesis of a trimeric ganglioside GM3 analogue.
A trimeric beta-lactosyl cluster based on 2-nitro-2-(hydroxymethyl)propane-1,3-diol was prepared using the trichloroacetimidate method. Kinetic studies showed that this cluster was an effective acceptor for rat-liver alpha-(2-->3)-sialyltransferase. Its KM was comparable to those for monomeric lactose and N-acetyllactosamine acceptors, and its Vmax was 1% of that measured for the LacNAc acceptor. Preparative-scale sialylation using this enzyme afforded a trimeric cluster of the ganglioside GM3 oligosaccharide in good yield. The NMR spectra of the trimeric GM3 analogue suggest that the oligosaccharide conformation is not significantly perturbed by this level of clustering.
Earle
M A
MA
Department of Chemistry, University of Manitoba, Winnipeg, Canada.
Manku
S
S
Hultin
P G
PG
Li
H
H
Palcic
M M
MM
D000606:Amino Sugars / Q000378:metabolism; D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005679:G(M3) Ganglioside / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000378:metabolism; D007700:Kinetics; D007785:Lactose / Q000031:analogs & derivatives / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000032:analysis / Q000737:chemistry; D051381:Rats; D012799:Sialyltransferases / Q000378:metabolism
D000606:Amino Sugars; D005679:G(M3) Ganglioside; D009005:Monosaccharides; C000458:N-acetyllactosamine; D012799:Sialyltransferases; D007785:Lactose