The crystal structure of IgE Fc reveals an asymmetrically bent conformation.
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.
Wan
Tommy
T
The Randall Centre, King's College London, New Hunt's House, London SE1 1UL, UK.
Beavil
Rebecca L
RL
Fabiane
Stella M
SM
Beavil
Andrew J
AJ
Sohi
Maninder K
MK
Keown
Maura
M
Young
Robert J
RJ
Henry
Alistair J
AJ
Owens
Ray J
RJ
Gould
Hannah J
HJ
Sutton
Brian J
BJ
D002236:Carbohydrate Conformation; D018360:Crystallography, X-Ray; D019281:Dimerization; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000737:chemistry*; D007073:Immunoglobulin E / Q000737:chemistry*; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D017455:Receptors, IgE / Q000737:chemistry
D007127:Immunoglobulin Constant Regions; D017455:Receptors, IgE; D007073:Immunoglobulin E