Comparison of N-glycosides of fetuins from different species and human alpha 2-HS-glycoprotein.
Complex type N-glycosides of commercial bovine fetuin preparations from pooled fetal calf serum have been shown to contain comparable amounts of Gal4,4,4TRI (see structure A below) and Gal4,4,3TRI (structure B) as major asialo-structures. To investigate whether there is a clear genetic specificity for synthesis of these oligosaccharides, N-glycosides from two preparations of bovine fetuin, each from a single calf, were examined. Both of these structures were present in each calf, and there was only a subtle quantitative difference in the ratio of these two structures between the calves. Thus, a specific galactosyltransferase, presumably required for the biosynthesis of the Gal4,4,3TRI structure, may exist in both of these individual calves. Comparison of fetuin N-glycosides was also extended to sheep, pig, and human alpha 2-HS-glycoprotein, the human counterpart of bovine fetuin, using high-pH anion-exchange chromatography of the reducing oligosaccharides as well as HPLC of their pyridinylamino derivatives. The N-glycosides of ovine fetuin also have both Gal4,4,4TRI and Gal4,4,3TRI structures in a ratio similar to that of bovine fetuin. However, the major N-glycoside of porcine fetuin is of a fucosyl biantennary complex type structure (structure C below) and human alpha 2-HS-glycoprotein has an N-glycoside which is almost exclusively a nonfucosylated biantennary structure (structure D). This species-specific presence of N-glycosides of fetuins and comparison with N-glycosides of other glycoproteins suggest that the polypeptide sequence of a glycoprotein may affect its N-glycan structure by regulating the activity of specific glycosyltransferases. [formula: see text]
Hayase
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T
Department of Biology, Johns Hopkins University, Baltimore, Maryland.
Rice
K G
KG
Dziegielewska
K M
KM
Kuhlenschmidt
M
M
Reilly
T
T
Lee
Y C
YC
D000581:Amidohydrolases / Q000494:pharmacology; D000595:Amino Acid Sequence; D000631:Aminopyridines / Q000737:chemistry; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry*; D002236:Carbohydrate Conformation / Q000187:drug effects; D002240:Carbohydrate Sequence; D002417:Cattle; D002852:Chromatography, Ion Exchange; D006027:Glycosides / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep; D013045:Species Specificity; D013552:Swine; D060749:alpha-2-HS-Glycoprotein; D000509:alpha-Fetoproteins / Q000737:chemistry*
C556354:AHSG protein, human; D000631:Aminopyridines; D001798:Blood Proteins; D006027:Glycosides; D009005:Monosaccharides; D009844:Oligosaccharides; D060749:alpha-2-HS-Glycoprotein; D000509:alpha-Fetoproteins; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase