The macrophage cell surface glycoprotein F4/80 is a highly glycosylated proteoglycan

Eur J Immunol. 1996 May;26(5):1139-46. doi: 10.1002/eji.1830260527.


Molecules whose expression is limited to particular leukocyte populations are of interest since they may perform unique functions for these cells. We therefore examined the biochemical nature of the F4/80 molecule, which is expressed solely on macrophage and dendritic cell subpopulations. Our study clearly indicates that post-translational modifications, which can influence both a protein's structural and functional features, constitute a major component of the 160-kDa cell-surface F4/80 molecule. The F4/80 molecule is synthesized as a single polypeptide chain which acquires numerous intramolecular disulfide bonds and requires an extended time period (T1/2 = 60 min) for transport to an endoglycosidase H-resistant form. The F4/80 molecule contains extensive N-linked glycosylation which contributes approximately 40 kDa to the mature molecule. The N-linked carbohydrates are of the branched, complex type, containing repeating N-acetylglycosamine or N-acetyllactosamine units which mediate the reactivity of the F4/80 molecule with Datura stramonium lectin. O-linked glycosylation is also present and contributes approximately 10 kDa to the F4/80 molecule. Furthermore, the sialic acid modifications of the F4/80 molecule are primarily through alpha 2-6 linkages to galactose. Finally, we demonstrate that the F4/80 molecule is a proteoglycan modified by chondroitin sulfate glycosaminoglycans. In addition to clarifying the nature of the F4/80 molecule biochemically, these post-translational modifications have specific implications for molecular recognition processes. We conclude that the modifications of the F4/80 molecule may mediate cell-cell recognition, cell adhesion, or ligand binding independently of the F4/80 molecule protein core.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Biological Transport / immunology
  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Glycosylation
  • Lectins / chemistry
  • Macrophages, Peritoneal / chemistry*
  • Macrophages, Peritoneal / immunology
  • Macrophages, Peritoneal / metabolism*
  • Membrane Glycoproteins / chemistry*
  • Membrane Glycoproteins / metabolism*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Molecular Weight
  • Protein Binding
  • Protein Processing, Post-Translational / immunology
  • Proteoglycans / chemistry*
  • Proteoglycans / immunology
  • Proteoglycans / metabolism*


  • Lectins
  • Membrane Glycoproteins
  • Proteoglycans