Structure of the carbohydrate moiety of human interferon-beta secreted by a recombinant Chinese hamster ovary cell line.
The carbohydrate structure of the major oligosaccharide of human interferon-beta (IFN-beta) synthesized by a genetically engineered Chinese hamster ovary cell line has been determined. Analysis of the glycopeptidase F-released carbohydrates by sequential exoglycosidase treatment, methylation analysis, and fast atom bombardment-mass spectrometry revealed that 95% of the IFN-beta oligosaccharides had the following structure: (Formula: see text). The remaining 5% of the carbohydrates are probably tri- or higher antennary oligosaccharide chains. The major oligosaccharide of the recombinant IFN-beta is remarkably homogeneous with respect to terminal galactose sialylation. NeuAc, which is alpha 2-3-linked to galactose in the human IFN-beta secreted by Chinese hamster ovary cells, can be re-incorporated with an alpha 2-6 linkage in vitro, into enzymatically desialylated IFN-beta using rat liver Gal beta 1-4GlcNAc alpha 2-6 sialyltransferase. The sugar chain is important for maintaining protein solubility as shown by the fact that IFN-beta protein precipitates after deglycosylation with glycopeptidase F.
Conradt
H S
HS
Department of Genetics, Gesellschaft für Biotechnologische Forschung mbH, Braunschweig, Federal Republic of Germany.
Egge
H
H
Peter-Katalinic
J
J
Reiser
W
W
Siklosi
T
T
Schaper
K
K
D000818:Animals; D002240:Carbohydrate Sequence; D002460:Cell Line; D006224:Cricetinae; D006031:Glycosylation; D007370:Interferon Type I / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis*; D011994:Recombinant Proteins / Q000032:analysis; D012799:Sialyltransferases / Q000494:pharmacology
D007370:Interferon Type I; D009844:Oligosaccharides; D011994:Recombinant Proteins; D012799:Sialyltransferases