A novel IgE-binding epitope of cat major allergen, Fel d 1

• Published in: Biochemical and biophysical research communications Vol. 470; no. 3; pp. 593 - 598
• Main Authors: Tasaniyananda, Natt, Tungtrongchitr, Anchalee, Seesuay, Watee, Sakolvaree, Yuwaporn, Indrawattana, Nitaya, Chaicumpa, Wanpen, Sookrung, Nitat
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 12.02.2016
• Subjects: Adolescent; Adult; Aged; Allergenic epitope; allergenicity; allergens; Allergens - chemistry; Allergens - immunology; Allergy; Amino Acid Sequence; Binding Sites; blood serum; Cat allergen; Cells, Cultured; Computer Simulation; cross reaction; epitopes; Epitopes, B-Lymphocyte - chemistry; Epitopes, B-Lymphocyte - immunology; Fel d 1; Female; Glycoproteins - chemistry; Glycoproteins - immunology; Humans; hypersensitivity; Hypersensitivity, Immediate - immunology; IgE blocking; immunoglobulin E; Immunoglobulin E - chemistry; Immunoglobulin E - immunology; immunotherapy; Male; mice; Models, Chemical; Molecular Docking Simulation; Molecular Sequence Data; monoclonal antibodies; patients; Protein Binding; Protein Conformation; Young Adult; Allergy; Allergenic epitope; Cat allergen; Fel d 1; IgE blocking
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2016.01.099

Information on the antigenic repertoire, especially the IgE-binding epitopes of an allergen is important for understanding the allergen induced immune response and cross-reactivity, as well as for generating the hypoallergenic variants for specific component resolved immunotherapy/diagnosis (CRIT and CRD). Data on the IgE-binding epitopes of cat allergens are scarce. In this study, a novel IgE-binding epitope of the cat major allergen, Fel d 1, was identified. Mouse monoclonal antibody (MAb) specific to the Fel d 1 was produced. Computerized intermolecular docking was used for determining the residues of the Fel d 1 bound by the specific MAb. The presumptive surface exposed residues of the Fel d 1 intrigued by the MAb are located on the chain 1. They are: L34 and T37 (helix 1); T39 (between helices 1 and 2); P40, E42 and E45 (helix 2); R61, K64, N65 and D68 (helix 3); and E73 and K76 (helix 4). The MAb competed efficiently with the cat allergic patients' serum IgE for Fel d 1 binding in the competitive IgE binding assay, indicating allergenicity of the MAb epitope. The newly identified allergenic epitope of the Fel d 1 is useful in a design of the CRIT and CRD for cat allergy. [Display omitted] •A novel B cell epitope of the cat major allergen, Fel d 1, was identified.•The epitope is conformational and IgE-binding or allergenic.•The epitope contains surface exposed residues of the Fel d 1 chain 1.•They are L34, T37, T39, P40, E42, E45, R61, K64, N65, D68, E73 and K76.•The epitope is useful for designing component resolved diagnosis/immunotherapy.