Title : Structure of
the carbohydrate moiety of human
interferon-beta secreted by a recombinant Chinese hamster ovary cell line
Abstract :
- 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