Isolation, Characterization and IgE Binding of Two 2S Albumins of Pomegranate Seeds

• Published in: Foods Vol. 13; no. 13; p. 1965
• Main Authors: Tuppo, Lisa, Alessandri, Claudia, Zaccaro, Laura, Giangrieco, Ivana, Tamburrini, Maurizio, Mari, Adriano, Ciardiello, Maria Antonietta
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21.06.2024
• Subjects: Albumin; Albumins; allergenicity; Allergens; Allergic reactions; Allergies; Amino acid sequence; Amino acids; Angioedema; Bioinformatics; Chitinase; food allergy; Fruits; hypersensitivity; Immunoblotting; Immunoglobulin E; Immunology; Mass spectrometry; Mass spectroscopy; N-terminal amino acid sequencing; polyacrylamide gel electrophoresis; pomegranates; Population studies; protein biochemistry; protein composition; protein purification; Protein structure; Proteins; seed extracts; seed storage proteins; Seeds; sensitization; United States > US; Italy; Germany; protein biochemistry; seed storage proteins; N-terminal amino acid sequencing; immunoblotting; bioinformatics; protein purification; mass spectrometry; sensitization; food allergy; Italian population
• ISSN: 2304-8158; 2304-8158
• DOI: 10.3390/foods13131965

Literature reports suggest that the presence of proteins in pomegranate seeds is responsible for sensitization and IgE-mediated allergic reactions. The objective of this study was the analysis of a pomegranate seed extract and the isolation and characterization of proteins contained in high amounts. The extract characterization showed a protein profile with main bands at about 18 kDa and below 10 kDa upon SDS-PAGE, and molecules were recognized by specific IgEs upon immunoblotting. Then, two new 2S albumins, a monomeric and a heterodimeric one, were isolated by using classical biochemical methods. They were identified via direct protein sequencing and mass spectrometry, and their primary structure was analyzed and compared with homologous allergenic proteins via bioinformatics. In an Italian population of 703 suspected allergic patients, analyzed by using the FABER® test, the frequency of sensitization to the monomeric and heterodimeric 2S albumins was 1.7% and 0.28%, respectively. This study reports for the first time the isolation and characterization of two 2S albumins from pomegranate seeds. The clinical relevance of these molecules needs further investigation, for instance in populations having different exposures and allergy profiles.