Polyclonal Immunoglobulin M: Location of Glycation Sites

Clin Chim Acta. 1992 Dec 31;213(1-3):23-35. doi: 10.1016/0009-8981(92)90218-f.

Abstract

A four step purification procedure for polyclonal human serum IgM was elaborated, including ultracentrifugation, ammonium sulfate and polyethyleneglycol precipitations and diffusion-exclusion gel chromatography. IgM was glycated in vitro both in the presence of [14C]glucose and with unlabeled glucose. Influence of incubation time up to 10 days and of glucose concentration between 10 and 60 mmol/l were studied. With 10 mmol/l glucose, a molar ratio glucose/IgM of 5.7 was attained in 10 days. Increase of glucose concentration up to 60 mmol/l led to a molar ratio of 16.0. Both basal and in vitro glycation were evaluated by 3H-labeling by gel filtration and Concanavalin A-Sepharose chromatographies. Glycation occurs mainly on the heavy chains (> 85%), particularly on the Fd region.

MeSH terms

  • Binding Sites
  • Chromatography, Affinity
  • Electrophoresis, Polyacrylamide Gel
  • Fructosamine
  • Glucose / metabolism*
  • Glycosylation
  • Hexosamines / analysis
  • Humans
  • Immunoglobulin M / blood*
  • Immunoglobulin M / isolation & purification
  • Peptide Fragments / metabolism
  • Tritium
  • Trypsin / metabolism

Substances

  • Hexosamines
  • Immunoglobulin M
  • Peptide Fragments
  • Tritium
  • Fructosamine
  • Trypsin
  • Glucose