Kinetic parameters of a beta-D-galactoside alpha 2 leads to 6 sialyltransferase from embryonic chicken liver.
A beta-D-galactoside alpha 2 leads to 6 sialyltransferase was purified 500-fold in 14% yield from 14-day embryonic chicken liver. Characterization of the product of the sialyltransferase catalysis was accomplished by separation and permethylation of double-labelled ([14C]NeuAc, [3H]Gal) oligosaccharides following their release from the glycoprotein fetuin by hydrazinolysis. The enzyme transfers NeuAc to Gal(beta 1 leads to 4)GlcNAc(beta 1 leads to)R-terminated oligosaccharides; no activity was found towards Gal(beta 1 leads to 3)GalNAc(alpha 1 leads to)R structures. The trisaccharide. NeuAc(alpha 2 leads to 6)Gal(beta 1 leads to 4)Glc, was shown to be a good inhibitor of the sialyltransferase. Kinetic investigations of the enzyme indicate it to have a sequential, random bi-bi mechanism.
D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002642:Chick Embryo; D007700:Kinetics; D008099:Liver / Q000196:embryology / Q000201:enzymology*; D009439:Neuraminidase / Q000378:metabolism; D012799:Sialyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D012995:Solubility; D014166:Transferases / Q000378:metabolism*; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D014166:Transferases; D012799:Sialyltransferases; D009439:Neuraminidase; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase