Biosynthesis of sulfated glycoprotein-N-glycans present in recombinant human tissue plasminogen activator.
Recombinant human tissue plasminogen activator expressed in murine epithelial cells carries, in part, sulfated N-glycans, which are characterized by the presence of a NeuAc alpha 3[SO4-6]Gal unit. In order to study the biosynthesis of this novel structural element, corresponding sulfated asialooligosaccharide alditols were resialylated in vitro using a crude sialyltransferase preparation from murine liver which was shown to contain Gal beta 1,3(4)GlcNAc alpha 2,3-sialyltransferase activity. Products were analyzed for transfer of sialic acid residues by anion-exchange HPLC. The results demonstrated that resialylation of SO4-6Gal-residues did not occur. Therefore, it may be concluded that transfer of the sulfate group is the final step in the biosynthesis of this structural epitope.
Pfeiffer
G
G
Institute of Biochemistry, University of Giessen, Germany.
Strube
K H
KH
Geyer
R
R
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D008099:Liver / Q000201:enzymology; D051379:Mice; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000302:isolation & purification / Q000378:metabolism*; D011134:Polysaccharides / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000096:biosynthesis*; D012799:Sialyltransferases / Q000378:metabolism; D013464:Sulfuric Acids / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000096:biosynthesis* / Q000235:genetics
D006023:Glycoproteins; D009844:Oligosaccharides; D011134:Polysaccharides; D011994:Recombinant Proteins; D013464:Sulfuric Acids; D012799:Sialyltransferases; C029156:N-acetyllactosaminide alpha-2,3-sialyltransferase; D010959:Tissue Plasminogen Activator