One- and Two-Dimensional Electrophoretic Identification of IgE-Binding Polypeptides ofLupinus albusand Other Legume Seeds

Abstract

The prevalence of food allergies in the world population requires integrated approaches to identify new potential allergens, especially those of plant origin. The aim of this work was the allergen in vitro analysis of Lupinus albus seed proteome, a promising food protein source, and the assessment of IgE cross-reactivities with other more diffused legume species. A combination of one- and two-dimensional gel electrophoresis and immunoblotting analyses with specific IgGs for band identification and lupin-sensitized patients' circulating IgEs for allergenicity studies has been used. Two lupin proteins, namely, conglutin gamma and 11S globulin basic subunits, strongly reacted with all patients' sera. Also, cross-reactivities with the homologous polypeptides of other legume species were observed. Otherwise, no reaction at all was detected with a 2S-type lupin protein. This global electrophoretic approach has allowed the identification of a new potential lupin allergen and confirmed the cross-reactivity among the legume 11S globulin basic subunits.

Immunoreactivity changes during lupin seed storage proteins digestion

“…The observed cross-reactivity may be due to the fact that the lupin β-conglutin fraction, within which the mentioned proteins are present and exhibits high sequence homology with the main peanut allergen Ara h 1 [31]. Magni et al [16] based on results obtained from 2-DE and immunoblotting stated that lupin proteins reacting with IgE antibodies of lupin sensitive individuals belong to fractions of α-and γ-conglutin. On the other hand, Goggin et al [17] utilising the same methods showed that major allergen of L. angustifolius are proteins from β-conglutin fraction.…”

“…In the case of lupin the most frequent reactions occurred in peanut sensitive individuals [5,6,14]. Fractions of α-and β-conglutin are considered to be the main proteins that cause allergic reactions in patients with known allergies to peanuts [15][16][17]. Recent studies in this subject were carried out by Ballabio et al [18].…”

Digestion susceptibility of seed globulins isolated from different lupin species

“…The ability to bind specific antibodies is especially important for the allergenicity of lupin seeds. The main IgE-binding proteins of lupin have molecular weights in the range from 70 to 60 kDa and 40 kDa (β-conglutin) [21], 30 and 17 kDa (γ-conglutin) [20] and 20 kDa (basic subunit of α-conglutin) [20]. Serious health risk associated with food allergy is the presence of cross-reactions, which in the case of lupin most often occurs with other legumes [18,19].…”

“…In the case of lupin, the most frequently observed cross-reaction is the one with peanut [9,10,18]. The main proteins that cause allergic reactions in patients with known allergies to peanuts are these included in the α-and β-conglutin fractions [19][20][21]. Ballabio et al [22] analysing the allergic reaction in twelve patients with allergy to peanuts found that seven of them reacted positively to β-conglutin.…”

A Review of Technologies for Detection and Measurement of Adulterants in Cereals and Cereal Products

“…Other cereal flour adulterants include, but are not limited to, mungbean powder in spirulina, cornstarch in lotus root powder, and lupin bean in wheat flour (Pompei et al, 1985;Parisot et al, 2001;Magni et al, 2005;Scarafoni et al, 2009).…”