Structural analysis and localization of the carbohydrate moieties of a soluble human interferon gamma receptor produced in baculovirus-infected insect cells.
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]
Manneberg
M
M
Department of Biology, F. Hoffmann-La Roche Ltd., Pharmaceutical Research-New Technologies, Basel, Switzerland.
Friedlein
A
A
Kurth
H
H
Lahm
H W
HW
Fountoulakis
M
M
D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000235:genetics*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005822:Genetic Vectors; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D009036:Moths; D017471:Receptors, Interferon / Q000737:chemistry* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry
D002241:Carbohydrates; D017471:Receptors, Interferon; D011994:Recombinant Proteins