Related Experiment Video
Updated: Sep 10, 2026

Identification and Characterization of Protein Glycosylation using Specific Endo- and Exoglycosidases
Published on: December 26, 2011
Unmasking a new recognition signal for O-linked glycosylation in the chorionic gonadotropin beta subunit
Vicenta Garcia-Campayo1, Tadashi Sugahara, Irving Boime
1Department of Molecular Biology and Pharmacology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA.
Abstract:
hCGbeta subunit is distinguished among the other members of the family of the glycoprotein hormones by the presence of four serine O-linked oligosaccharide units in the last 25 amino acids. This carboxy terminal peptide (CTP) influences the intracellular behavior of the subunit and is important for maintaining the biological half-life of hCG. To examine how the O-linked oligosaccharides affect the metabolic behavior of hCG, we generated a CGbeta mutant devoid of the native O-linked acceptor sites. An alternative site not used in the native subunit was glycosylated and the structure of this oligosaccharide differed from the wild-type O-linked carbohydrates. This glycosylation occurred at serine 130 in the CTP and in contrast to the wild type O-linked oligosaccharides, sialic acid is a major component of the alternatively linked carbohydrate. The data show that deleting the native acceptor sites exposes a new site for O-glycosylation and promotes a differential intracellular processing of the beta subunit. These results support the hypothesis that the CTP participates in the folding of the newly synthesized subunit, which is manifested by the post-translational changes reported here.
Related Concept Videos
Protein Glycosylation
Glycosylation occurs in...
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
Protein Folding Quality Check in the RER
Transcytosis of IgG
IgG molecules from a mother undergo transcytosis starting around 13 weeks of gestation. The amount of IgG transferred and entering the fetal blood circulation increases with...
Proteoglycans

