Molecular characterization of major allergens Ara h 1, 2, 3 in peanut seed

Abstract

Peanut is among the most commonly used dietary seeds, but peanut allergens, especially Ara h 1 (Arachis hypogaea allergy 1), 2 and 3, can cause severe IgE-mediated reactions. In this study, the molecular characterization and expression pattern of three allergens in peanut LUHUA 8, the representative of the cultivated lines in China, are reported. In situ hybridization and real time PCR analysis revealed high expression levels and different tissue expression patterns of the three allergens, which might be connected with many aspects, such as the strong conservation of intron phase of the allergen genes, the low energy of the mRNA's regions, and the complicated post-translational modifications. Furthermore, the different sequences between the cloned allergens and the reported sequences previously involved the charged amino acids especially in IgE epitopes, which might alter specific physicochemical and physiological properties, and thus influence the immunity of the allergens. The identification of the specific features of the allergen genes would be of considerable importance to the basic understanding of the specific characteristics of peanut seed allergens.

Genome-wide mining seed-specific candidate genes from peanut for promoter cloning

“…Notably, SSCG1-12 was extremely highly expressed in the seeds, and specifically, SSCG1 and SSCG6 were abundantly expressed during all five seed development stages (Fig 2). Functional prediction analysis revealed that these SSCGs encoded nutrient reservoir proteins or allergen proteins (Table 1), whose transcripts are considered widely expressed specifically in mature peanut seed [38,39].…”

Combined N-Glycome and N-Glycoproteome Analysis of the Lotus japonicus Seed Globulin Fraction Shows Conservation of Protein Structure and Glycosylation in Legumes

“…Food allergy is an increasing problem and legume seed proteins frequently cause allergic responses. ,,− As a first step in determining whether glycosylation of legume proteins has a role in food allergy the N-glycome of the Lotus seed globulins including the abundant LCP2, the homologue of peanut Ara h 1, was determined. The N-glycans were released in-solution using PNGase A followed by characterization and relative quantification using PGC-LC–MS/MS.…”

“…All of these are insoluble in water but soluble in high-salt solvents. Several seed globulins are known to be allergens. , The general assumption is that legume food allergy is caused by aberrant proteolytic digestion in the gastrointestinal tract where proteolytic enzymes are located. − Partially degraded peptides of more than six to eight amino acid residues can cross into the blood circulation with their epitopes exposed on MCH II receptors on antigen-presenting B-cells. Following initial exposure to such an allergen, specific IgE antibodies will be produced that maintain a background level over time.…”

“…Several seed globulins are known to be allergens. 12,13 The general assumption is that legume food allergy is caused by aberrant proteolytic digestion in the gastrointestinal tract where proteolytic enzymes are located. 14−16 of more than six to eight amino acid residues can cross into the blood circulation with their epitopes exposed on MCH II receptors on antigen-presenting B-cells.…”