Structure of the asparagine-linked sugar chains of alpha-fetoprotein purified from human ascites fluid.
alpha-Fetoprotein purified from human serum was found to contain an asparagine-linked sugar chain in one molecule. The sugar chain was quantitatively released from the polypeptide moiety by hydrazinolysis and recovered as oligosaccharides after N-acetylation. The oligosaccharide mixture was separated into a neutral (N) and two acidic (A-1 and A-2) fractions by paper electrophoresis. By combination of sequential exoglycosidase digestion, methylation analysis, and concanavalin A-Sepharose column chromatography, the structures of these fractions were determined to be: Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GLcNAc beta 1 leads to 4(+/- Fuc alpha 1 leads to 6)GlcNAc; Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(+/- Fuc alpha 1 leads to 6(GlcNAc; and NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4(+/- Fuc alpha 1 leads to 6)GlcNAc.
D001202:Ascitic Fluid / Q000032:analysis; D001216:Asparagine; D002240:Carbohydrate Sequence; D006801:Humans; D009844:Oligosaccharides / Q000032:analysis; D012794:Sialic Acids / Q000032:analysis; D000509:alpha-Fetoproteins
D009844:Oligosaccharides; D012794:Sialic Acids; D000509:alpha-Fetoproteins; D001216:Asparagine