Structural and Immunologic Properties of the Major Soybean Allergen Gly m 4 Causing Anaphylaxis

Abstract

Gly m 4 is the major soybean allergen, causing birch pollen cross allergic reactions. In some cases, Gly m 4-mediated anaphylaxis takes place, but the causative factors are still unknown. Here, we studied the structural and immunologic properties of Gly m 4 to shed light on this phenomenon. We showed that Gly m 4 retained its structure and IgE-binding capacity after heating. Gly m 4 was cleaved slowly under nonoptimal gastric conditions mimicking duodenal digestion, and IgE from the sera of allergic patients interacted with the intact allergen rather than with its proteolytic fragments. Similar peptide clusters of Bet v 1 and Gly m 4 were formed during allergen endolysosomal degradation in vitro, but their sequence identity was insignificant. Animal polyclonal anti-Gly m 4 and anti-Bet v 1 IgG weakly cross-reacted with Bet v 1 and Gly m 4, respectively. Thus, we supposed that not only conserved epitopes elicited cross-reactivity with Bet v 1, but also variable epitopes were present in the Gly m 4 structure. Our data suggests that consumption of moderately processed soybean-based drinks may lead to the neutralizing of gastric pH as a result of which intact Gly m 4 can reach the human intestine and cause IgE-mediated system allergic reactions.

Structural and Immunological Features of PR-10 Allergens: Focusing on the Major Alder Pollen Allergen Aln g 1

“…These results were in c data that were previously obtained for soybean Gly m 4. At 98 °C, the s protein unfolded, but after cooling down to 20 °C, the refolding of Gly m 4 However, as previously described, during heating, Bet v 1 underwent an cess to a random coil structure and partly restored its structure after rec presence of lysolipid LPPG increased the percentage of α-helices in the A and provided greater resistance of the allergen to thermal denaturation, us earlier for soybean Gly m 4 [27] (Figure 3, Table 1).…”

“…These results were in contrast with our data that were previously obtained for soybean Gly m 4. At 98 • C, the soybean allergen protein unfolded, but after cooling down to 20 • C, the refolding of Gly m 4 took place [27]. However, as previously described, during heating, Bet v 1 underwent an unfolding process to a random coil structure and partly restored its structure after recooling [24].…”

Soybean Allergen Detection for Hypoallergenicity Validation of Natto-A Fermented Soybean Food

“…Because soybeans are used in a variety of processed foods, it is conceivable that these multiple allergens may be variably altered by processing methods; however, few studies have conducted a comprehensive variation analysis of such soybean allergens. We generated antibodies against many soybean allergens and analyzed the variation in multiple soybean allergens after gamma irradiation, insect damage, and GM soybeans . Regarding the processing methods, we comprehensively detected soy allergens in miso, a fermented soybean food, and showed that various allergen levels were differentially reduced in different types of miso .…”

“…We generated antibodies against many soybean allergens and analyzed the variation in multiple soybean allergens after gamma irradiation, 38 insect damage, 36 and GM soybeans. 39 Regarding the processing methods, we comprehensively detected soy allergens in miso, a fermented soybean food, and showed that various allergen levels were differentially reduced in different types of miso. 20 In this study, we analyzed the variations in various allergens related to natto, another typical fermented food derived from soybeans.…”

“…Most of the antibodies used in the present study were checked for reactivity and specificity, which were also used in our previous studies. 20,[35][36][37][38][39]41 2.10. Statistical Analysis.…”