Title : Structural analysis and localization of
the carbohydrate moieties of a soluble human
interferon gamma receptor produced in baculovirus-infected insect cells
Abstract :
- A soluble form of the human interferon gamma receptor that is required for the identification of interferon gamma antagonists was expressed in baculovirus-infected insect cells
- The protein carried N-linked carbohydrate and showed a heterogeneity on denaturing polyacrylamide gels
- We investigated the utilization of the potential sites for N-linked glycosylation and the structure of the carbohydrate moieties of this soluble receptor
- Amino acid sequence analysis and ion spray mass spectrometry revealed that of the five potential sites for N-linked glycosylation, Asn17 and Asn69 were always utilized, whereas Asn62 and Asn162 were utilized in approximately one-third of the protein population
- Asn223 was never found to be glycosylated
- The soluble receptor was treated with N-glycosidase F and the oligosaccharides released were analyzed by matrix-assisted laser desorption mass spectrometry, which showed that the protein carried six types of short carbohydrate chains
- The predominant species was a hexasaccharide of molecular mass 1,039 , containing a fucose subunit linked to the proximal N-acetylglucosamine residue: [formula: see text