A comparative study of the N-linked oligosaccharide structures of human IgG subclass proteins.
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.
Jefferis
R
R
Department of Immunology, University of Birmingham Medical School, Edgbaston, U.K.
Lund
J
J
Mizutani
H
H
Nakagawa
H
H
Kawazoe
Y
Y
Arata
Y
Y
Takahashi
N
N
D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis* / Q000145:classification; D008969:Molecular Sequence Data; D009101:Multiple Myeloma / Q000378:metabolism; D009844:Oligosaccharides / Q000032:analysis*; D010266:Paraproteins / Q000032:analysis* / Q000145:classification
D007074:Immunoglobulin G; D009844:Oligosaccharides; D010266:Paraproteins