Detection and Characterization of the Soybean Allergen Gly m 7 in Soybeans and Processed Soybean Foods

Ayano Fukuzumi,Erika Yano,Nobuhiro Zaima,Naoki Tokumasu,Ayato Matsuo,Tatsuya Moriyama

doi:10.3390/allergies1040022

Abstract

Gly m 7, a novel soybean allergen, was recently reported. In this study, we attempted to detect Gly m 7 in various soybeans and processed soybean foods using raised anti-Gly m 7 antibodies and enzyme-linked streptavidin, specifically binding to the biotin moiety of Gly m 7. There was a large difference in Gly m 7 levels in various soybean-processed foods. When Gly m 7 levels were determined, all cultivars contained this allergen almost completely, but the biotin moiety detected by streptavidin varied, suggesting that biotinylated levels of Gly m 7 might differ among cultivars. The thermal stability of Gly m 7 was determined by heating soybean extracts. During detection using anti-peptide antibodies, detectable intact Gly m 7 was gradually reduced by heating. Gly m 7 was not detected by peptide or biotin detection in worm-wounded soybeans. Soybeans were immersed in distilled water as a pretreatment step for germination, and Gly m 7 levels were compared by immersion time (4–96 h). Intact Gly m 7 was rapidly degraded in detection by both peptide and biotin moieties. This suggested that Gly m 7 was degraded by some protease(s) during germination. These results would be useful for understanding the properties or risk assessment of Gly m 7, a newly discovered soybean allergen.

Highlights

Soybeans (Glycine max L.) are a common ingredient in many foods, including fermented foods, in both traditional Asian and Western cuisines
A dose-dependent increase in the absorbance of the soybean extract was confirmed by enzyme-linked immunosorbent assay (ELISA)
We detected immunoreactive protein bands at approximately 70 kDa, which is consistent with the molecular weight (MW) of Gly m 7 (Figure 2b, lane 1)

Summary

Introduction

Soybeans (Glycine max L.) are a common ingredient in many foods, including fermented foods, in both traditional Asian and Western cuisines. Properties of soybean protein make it an excellent choice for food processing widely used as an additive in various processed foods. Soybean protein has received a great deal of attention in recent years as a material for “veggie meat” [4,5]. Consumption of soybeans can cause allergic reactions in some individuals, and various allergens have already been identified in soybeans [6]. The major allergens of soybeans are the Kunitz soybean trypsin inhibitor [7]; Gly m Bd 30 K [8,9]; Gly m Bd

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