Isolation and characterization of relevant allergens from boiled lentils - 04/09/11
Abstract |
Background: Lentils seem to be the most common legume implicated in pediatric allergic patients in the Mediterranean area. However, no lentil allergen has been isolated and characterized. Objective: We sought to purify and characterize relevant IgE-binding proteins from boiled lentil extracts. Methods: IgE-binding proteins from crude and boiled lentil extracts were detected with a pool of sera from patients with lentil allergy. Allergens were isolated by gel-filtration chromatography followed by cation- and anion-exchange chromatography or by reverse-phase HPLC. Their characterization included N-terminal amino acid sequencing, complex asparagine-linked glycan detection, specific IgE immunodetection with 22 individual sera from allergic patients, and immunoblot and CAP inhibition assays. Results: Heat treatment of lentils produced substantial changes in the SDS-PAGE patterns of whole extracts, mainly a strong increase of 12- to 16-kd bands and a decrease of 25- to 45-kd components. Major IgE-binding proteins from the boiled lentil extract were located in the 12- to 16-kd and 45- to 70-kd ranges. Two allergens of 16 kd, proteins L1 and L2, and another one of 12 kd, protein L3, were purified. N-terminal sequencing indicated that all 3 were related and allowed their identification as γ-vicilin subunits. Protein L1 was recognized by 68% of the individual sera tested and inhibited 64% of the IgE binding by commercial lentil CAPs. A second type of allergen of 66 kd, named protein H, was also isolated and identified as a seed-specific biotinylated protein. Protein H reacted with 41% of the individual sera and produced 45% inhibition in CAP inhibition assays. Conclusions: Two different types of allergens have been identified in boiled lentils. Those of 12 to 16 kd, called Len c 1, correspond to γ-vicilin subunits, and those of 66 kd, designated Len c 2, correspond to seed-specific biotinylated protein. Homology with proteins from other legume species can explain potential cross-reactions among these foods. (J Allergy Clin Immunol 2000;106:955-61.)
Le texte complet de cet article est disponible en PDF.Keywords : Lentil, allergen isolation, vicilin subunit, biotinylated protein, legumes
Abbreviations : PVDF:, RP-HPLC:
Plan
![]() | Supported by Dirección General de Enseñanza Superior e Investigación Científica, MEC (grant PB98-0735). |
![]() ![]() | Reprint requests: Gabriel Salcedo, PhD, Unidad de Bioquímica, Departamento de Biotecnología, E.T.S. Ingenieros Agrónomos, 28040 Madrid, Spain. |
Vol 106 - N° 5
P. 955-961 - novembre 2000 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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