Catalytic folding of the Cepsilon3 domain by its high affinity receptor.
The interaction of immunoglobulin E (IgE) with its cellular receptor FcepsilonRIalpha is a central regulator of allergy. Structural studies have identified the third domain (Cepsilon3) of the constant region of epsilon heavy chain as the receptor binding region. The isolated Cepsilon3 domain is a "molten globule" that becomes structured upon binding of the FcepsilonRIalpha ligand. In this study, fluorescence and nuclear magnetic resonance spectroscopies are used to characterise the role of soluble FcepsilonRIalpha in the folding of the monomeric Cepsilon3 domain of IgE. Soluble FcepsilonRIalpha is shown to display characteristic properties of a catalyst for the folding of Cepsilon3, with the rate of Cepsilon3 folding being dependent on the concentration of the receptor.
Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
Naomi E
NE
Harwood
Nicholas C
NC
Price
James M
JM
McDonnell
D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D000818:Animals; D002384:Catalysis; D005453:Fluorescence; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism; D007139:Immunoglobulin epsilon-Chains / Q000737:chemistry* / Q000378:metabolism*; D051379:Mice; D019906:Nuclear Magnetic Resonance, Biomolecular; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D017455:Receptors, IgE / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014364:Tryptophan / Q000031:analogs & derivatives / Q000737:chemistry
D000817:Anilino Naphthalenesulfonates; D007141:Immunoglobulin Fc Fragments; D007139:Immunoglobulin epsilon-Chains; D017455:Receptors, IgE; D011994:Recombinant Proteins; C006657:7-azatryptophan; C027132:1-anilino-8-naphthalenesulfonate; D014364:Tryptophan