Alteration of N-linked oligosaccharide structures of human chorionic gonadotropin β-subunit by disruption of disulfide bonds

Takayuki Moriwaki, Nobuhiko Suganuma, Madoka Furuhashi, Fumitaka Kikkawa, Yutaka Tomoda, Irving Boime, Munehiro Nakata, Tsuguo Mizuochi

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

The human chorionic gonadotropin and subunit (hCGβ) is a glycoprotein in which 12 cysteine residues pair to form six intramolecular disulfide bonds. In order to elucidate the effect of each disulfide bond on glycosylation of the molecule, we analysed structures of asparagine-linked oligosaccharides of various recombinant hCGβ produced in Chinese hamster ovary (CHO) cells: wild-type hCGβ (βWT) and mutants in which any one of the six intramolecular disulfide bonds had been disrupted by site-directed mutagenesis. SDS-PAGE analysis of βWT and these mutants before and after digestion with endoglycosidase F and H revealed structural changes in the oligosaccharide moieties of some mutants. In addition, structural analysis of oligosaccharides obtained from metabolically labeled βWT and a mutant showed that the mutant contained additional high mannose type oligosaccharides. These results suggest that elimination of a specific disulfide bond, resulting in a change in the protein conformation, disturbs the normal assembly of the mature complex type oligosaccharides in the hCGβ molecule.

Original languageEnglish
Pages (from-to)225-229
Number of pages5
JournalGlycoconjugate Journal
Volume14
Issue number2
DOIs
StatePublished - 1997

Keywords

  • Disulfide bond
  • Human chorionic gonadotrophin
  • N-linked oligosaccharide processing
  • hCGβ-subunit

Fingerprint Dive into the research topics of 'Alteration of N-linked oligosaccharide structures of human chorionic gonadotropin β-subunit by disruption of disulfide bonds'. Together they form a unique fingerprint.

Cite this