TY - JOUR TI - Visualization of clustered IgE epitopes on α-lactalbumin AU - Hochwallner, H. AU - Schulmeister, U. AU - Swoboda, I. AU - Focke-Tejkl, M. AU - Civaj, V. AU - Balic, N. AU - Nystrand, M. AU - Härlin, A. AU - Thalhamer, J. AU - Scheiblhofer, S. AU - Keller, W. AU - Pavkov, T. AU - Zafred, D. AU - Niggemann, B. AU - Quirce, S. AU - Mari, A. AU - Pauli, G. AU - Ebner, C. AU - Papadopoulos, N.G. AU - Herz, U. AU - van Tol, E.A.F. AU - Valenta, R. AU - Spitzauer, S. JO - Allergy: European Journal of Allergy and Clinical Immunology PY - 2010 VL - 125 TODO - 6 SP - 1279-1285.e9 PB - SN - null TODO - 10.1016/j.jaci.2010.03.007 TODO - alpha lactalbumin; immunoglobulin E antibody, allergenicity; article; basophil degranulation; circular dichroism; controlled study; diagnostic value; epitope mapping; Escherichia coli; gastrointestinal symptom; histamine release; human; mass spectrometry; microarray analysis; milk allergy; nonhuman; priority journal; protein expression; protein folding; protein purification; protein structure; thermostability, Animals; Cattle; Cells, Cultured; Circular Dichroism; Cloning, Molecular; Epitopes, B-Lymphocyte; Escherichia coli; Feasibility Studies; Histamine Release; Humans; Immunoglobulin E; Lactalbumin; Mass Spectrometry; Microarray Analysis; Milk Hypersensitivity; Peptide Fragments; Recombinant Proteins TODO - Background: α-Lactalbumin (α-La) is a major cow's milk (CM) allergen responsible for allergic reactions in infants. Objective: We performed molecular, structural, and immunologic characterization of α-La. Methods: Recombinant α-lactalbumin (rα-La) was expressed in Escherichia coli, purified to homogeneity, and characterized by means of mass spectrometry and circular dichroism, and its allergenic activity was studied by using microarray technology, as well as in a basophil histamine release assay. IgE epitope mapping was performed with synthetic peptides. Results: According to circular dichroism analysis, rα-La represented a folded protein with a high thermal stability and refolding capacity. rα-La reacted with IgE antibodies from 57.6% of patients with CM allergy (n = 66) and induced the strongest basophil degranulation with sera from patients with CM allergy who had exhibited gastrointestinal symptoms or severe systemic reactions on CM exposure. rα-La contained sequential and conformational IgE epitopes. Superposition of IgE-reactive peptides onto the 3-dimensional structure of α-La revealed a close vicinity of the N- and C-terminal peptides within a surface-exposed patch. Conclusions: rα-La can be used for the diagnosis of patients with severe allergic reactions to CM and serves as a paradigmatic tool for the development of therapeutic strategies for CM allergy. © 2010 American Academy of Allergy, Asthma & Immunology. ER -