Title
The amyloid fold of Gad m 1 epitopes governs IgE binding
Author
Rosa Sánchez, Javier Martínez, Ana Castro, María Pedrosa, Santiago Quirce, Rosa Rodríguez-Pérez, María Gasset
Year
2016
Journal
Scientific Reports
Abstract
Amyloids are polymeric structural states formed from locally or totally unfolded protein chains that permit surface reorganizations, stability enhancements and interaction properties that are absent in the precursor monomers. β-Parvalbumin, the major allergen in fish allergy, forms amyloids that are recognized by IgE in the patient sera, suggesting a yet unknown pathological role for these assemblies. We used Gad m 1 as the fish β-parvalbumin model and a combination of approaches, including peptide arrays, recombinant wt and mutant chains, biophysical characterizations, protease digestions, mass spectrometry, dot-blot and ELISA assays to gain insights into the role of amyloids in the IgE interaction. We found that Gad m 1 immunoreactive regions behave as sequence-dependent conformational epitopes that provide a 1000-fold increase in affinity and the structural repetitiveness required for optimal IgE binding and cross-linking upon folding into amyloids. These findings support the amyloid state as a key entity in type I food allergy.
Full Article
Instrument
J-820
Keywords
Circular dichroism, Secondary structure, Thermal stability, Protein denaturation, Thermodynamics, Biochemistry