The crystal structure of IgE Fc reveals an asymmetrically bent conformation

Nat Immunol. 2002 Jul;3(7):681-6. doi: 10.1038/ni811. Epub 2002 Jun 17.


The distinguishing structural feature of immunoglobulin E (IgE), the antibody responsible for allergic hypersensitivity, is the C epsilon 2 domain pair that replaces the hinge region of IgG. The crystal structure of the IgE Fc (constant fragment) at a 2.6-A resolution has revealed these domains. They display a distinctive, disulfide-linked Ig domain interface and are folded back asymmetrically onto the C epsilon 3 and C epsilon 4 domains, which causes an acute bend in the IgE molecule. The structure implies that a substantial conformational change involving C epsilon 2 must accompany binding to the mast cell receptor Fc epsilon RI. This may be the basis of the exceptionally slow dissociation rate of the IgE-Fc epsilon RI complex and, thus, of the ability of IgE to cause persistent allergic sensitization of mast cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Conformation
  • Crystallography, X-Ray
  • Dimerization
  • Humans
  • Immunoglobulin Constant Regions / chemistry*
  • Immunoglobulin E / chemistry*
  • Models, Molecular
  • Protein Structure, Tertiary
  • Receptors, IgE / chemistry


  • Immunoglobulin Constant Regions
  • Receptors, IgE
  • Immunoglobulin E

Associated data

  • PDB/1LS0