Characterization of FcR Ig-binding sites and epitope mapping

Immunomethods. 1994 Feb;4(1):17-24. doi: 10.1006/immu.1994.1003.


The low-affinity receptor for IgG, Fc gamma RII, and the high-affinity receptor for IgE, Fc epsilon RI, are functionally distinct but structurally homologous receptors. These characteristics have been exploited using a chimeric receptor strategy to examine segments of human Fc gamma RII for IgG-binding function. A series of chimeric receptors was generated by exchanging coding regions of the extracellular ligand-binding regions between Fc gamma RII and the Fc epsilon RI alpha chain using splice overlap extension by the polymerase chain reaction. The expression of these chimeric receptors in COS-7 cells and analysis of their IgG/IgE binding capacities have enabled the Ig-binding region of Fc gamma RII to be localized to a subregion of the second extracellular domain. The localization of the Ig-binding region of Fc gamma RII has provided the opportunity of performing site-directed mutagenesis to determine the key amino acids involved in the interaction of the receptor with IgG. These findings demonstrate that the chimeric receptor approach is a powerful technique for the dissection of structure/function relationships of structurally related yet functionally different molecules.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal
  • Base Sequence
  • Binding Sites
  • Cell Line
  • Epitopes / analysis*
  • Fluorescent Antibody Technique
  • Humans
  • Immunoglobulin G / metabolism*
  • Mice
  • Molecular Sequence Data
  • Oligonucleotides / chemistry
  • Receptors, IgE / genetics
  • Receptors, IgE / metabolism
  • Receptors, IgG / genetics
  • Receptors, IgG / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Rosette Formation
  • Transfection


  • Antibodies, Monoclonal
  • Epitopes
  • Immunoglobulin G
  • Oligonucleotides
  • Receptors, IgE
  • Receptors, IgG
  • Recombinant Fusion Proteins