Screening neutral and acidic IgG N-glycans by high density electrophoresis

Glycoconj J. 1999 Jun;16(6):283-90. doi: 10.1023/a:1007014028905.

Abstract

IgG carries bi-antennary N-linked glycans which differ in degrees of galactosylation, core fucosylation and bisecting N-acetyl glucosamine. The majority of these are non-sialyated closely related neutral structures which can be resolved by HPLC analysis, but which are difficult to separate in techniques such as fluorophore-coupled carbohydrate electrophoresis. Derivatisation with the singly charged fluorophore, 2-amino benzoic acid and separation in gels with a 30% monomer content in tris/glycine buffer enabled separation of neutral glycans. In particular, agalactosyl glycans with either a core fucose substitution or bisecting N-acetyl galactosamine could be resolved. Good separation of mono- and di-galactosylated glycans was also achieved with this system. It was shown that IgG can be separated from serum by size-exclusion and anion exchange chromatography with minimal contamination, with complete glycan release accomplished by the enzyme peptide-N-glycosidase F (F. meningosepticum). This method of resolving IgG glycans could be used to monitor patients in which glycosylation changes may have a diagnostic value, as in rheumatoid arthritis. It could also be used to monitor recombinant IgG glycosylation where routine screening is required in the biotechnology industry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, High Pressure Liquid
  • Electrophoresis, Polyacrylamide Gel / methods
  • Fluorescent Dyes
  • Glycosylation
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin G / chemistry*
  • Immunoglobulin G / isolation & purification
  • Polysaccharides / blood
  • Polysaccharides / chemistry*
  • ortho-Aminobenzoates

Substances

  • Fluorescent Dyes
  • Immunoglobulin G
  • Polysaccharides
  • ortho-Aminobenzoates
  • anthranilic acid