PMID- 9398285
OWN - NLM
STAT- MEDLINE
DCOM- 19980127
LR  - 20061115
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 36
IP  - 50
DP  - 1997 Dec 16
TI  - Participation of the N-terminal region of Cepsilon3 in the binding of human IgE 
      to its high-affinity receptor FcepsilonRI.
PG  - 15568-78
AB  - The binding of immunoglobulin E (IgE) to its high-affinity receptor (FcepsilonRI) 
      expressed on mast cells and basophils is central to the development of an 
      allergic reaction. Previous studies have implicated the third constant domain of 
      IgE-Fc (Cepsilon3) as the site of the interaction with FcepsilonRI. We have 
      prepared a series of site-directed mutants of human IgE-Fc, particularly focusing 
      on the N-terminal "linker" region and AB loop of Cepsilon3. The kinetics of 
      binding IgE and its Fc fragments to the immobilized receptor were determined by 
      surface plasmon resonance (SPR), and two phases of binding were observed. We 
      identified one mutation in the N-terminal linker region, R334S, that has a 
      dramatic effect on binding. R334S lowers the affinity of IgE-Fc for FcepsilonRI 
      by 120-fold, principally through an increase in the dissociation rate of the 
      slower phase of the interaction. This mutation has a similar effect in 
      Fcepsilon3-4, a truncated form of IgE-Fc which lacks the Cepsilon2 domain pair, 
      and thus it does not exert its effect through altering the quaternary structure 
      of IgE-Fc, firmly implicating Arg334 as a contact residue in the complex. However 
      R334S has no effect on the binding of FcepsilonRII (CD23), the low-affinity 
      receptor for IgE, demonstrating the structural integrity of the mutated IgE-Fc. 
      Circular dichroism spectroscopy and thermal stability studies further indicate 
      that the R334S mutation does not disorder or destabilize the structure of IgE-Fc 
      or Fcepsilon3-4. These results demonstrate the importance of the N-terminal 
      linker region of Cepsilon3 in the interaction of IgE with FcepsilonRI.
FAU - Henry, A J
AU  - Henry AJ
AD  - The Randall Institute, King's College London, 26-29 Drury Lane, London, WC2B 5RL, 
      United Kingdom.
FAU - Cook, J P
AU  - Cook JP
FAU - McDonnell, J M
AU  - McDonnell JM
FAU - Mackay, G A
AU  - Mackay GA
FAU - Shi, J
AU  - Shi J
FAU - Sutton, B J
AU  - Sutton BJ
FAU - Gould, H J
AU  - Gould HJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Immunoglobulin Fc Fragments)
RN  - 0 (Immunoglobulin epsilon-Chains)
RN  - 0 (Receptors, IgE)
RN  - 0 (Recombinant Proteins)
RN  - 37341-29-0 (Immunoglobulin E)
SB  - IM
MH  - Animals
MH  - Biosensing Techniques
MH  - Chromatography, Gel
MH  - Circular Dichroism
MH  - Humans
MH  - Immunoglobulin E/chemistry/genetics/*metabolism
MH  - Immunoglobulin Fc Fragments/chemistry/genetics/*metabolism
MH  - Immunoglobulin epsilon-Chains/chemistry/genetics/*metabolism
MH  - Kinetics
MH  - Mice
MH  - Models, Molecular
MH  - Mutagenesis, Site-Directed
MH  - Protein Binding
MH  - Protein Conformation
MH  - Protein Folding
MH  - Rats
MH  - Receptors, IgE/*metabolism
MH  - Recombinant Proteins/metabolism
MH  - Sequence Homology, Amino Acid
MH  - Temperature
MH  - Transfection
EDAT- 1998/01/31 00:00
MHDA- 1998/01/31 00:01
CRDT- 1998/01/31 00:00
PHST- 1998/01/31 00:00 [pubmed]
PHST- 1998/01/31 00:01 [medline]
PHST- 1998/01/31 00:00 [entrez]
AID - bi971299+ [pii]
AID - 10.1021/bi971299+ [doi]
PST - ppublish
SO  - Biochemistry. 1997 Dec 16;36(50):15568-78. doi: 10.1021/bi971299+.