A comparative study of the N-linked oligosaccharide structures of human IgG subclass proteins

Biochem J. 1990 Jun 15;268(3):529-37. doi: 10.1042/bj2680529.


Quantitative oligosaccharide profiles were determined for each of 18 human IgG paraproteins representing the four subclasses. Each paraprotein exhibits a unique profile that may be substantially different from that observed for polyclonal IgG. The IgG2 and some IgG3 proteins analysed exhibit a predominance of oligosaccharide moieties having galactose on the Man(alpha 1----3) arm rather than the Man(alpha 1----6) arm; it was previously held that galactosylation of the Man(alpha 1----6) arm is preferred, as observed for IgG1, IgG4 and polyclonal IgG. An IgG4 protein is reported that has galactosylated Man(alpha 1----3) and Man(alpha 1----6) arms on both Fc-localized carbohydrate moieties; previous findings suggested that such fully glycosylated structures could not be accommodated within the internal space of the C gamma 2 domains. Unusual monoantennary oligosaccharides present in IgG2 and IgG3 proteins were isolated and their structures determined.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Sequence
  • Chromatography, High Pressure Liquid
  • Humans
  • Immunoglobulin G / analysis*
  • Immunoglobulin G / classification
  • Molecular Sequence Data
  • Multiple Myeloma / metabolism
  • Oligosaccharides / analysis*
  • Paraproteins / analysis*
  • Paraproteins / classification


  • Immunoglobulin G
  • Oligosaccharides
  • Paraproteins