Allergenicity of Soybean: New Developments in Identification of Allergenic Proteins, Cross-Reactivities and Hypoallergenization Technologies

Abstract

Soybean is considered one of the "big eight" foods that are believed to be responsible for 90% of all allergenic reactions. Soy allergy is of particular importance, because soybeans are widely used in processed foods and, therefore, represent a particularly insidious source of hidden allergens. Although significant advances have been made in the identification and characterization of soybean allergens, scientists are not completely certain about which proteins in soy cause allergic reactions. At least 16 allergens have been identified. Most of them, as with other plant food allergens, have a metabolic, storage, or protective function. These allergens belong to protein families which have conserved structural features in relation with their biological activity, which explains the wide immunochemical cross-recognition observed among members of the legume family. Detailed analysis of the structure-allergenicity relationships has been hampered by the complexity and heterogeneity of soybean proteins. A variety of technological approaches have been attempted to decrease soybean allergenicity. This paper provides a comprehensive review of the current body of knowledge on the identification and characterization of soybean allergens, as well as an update on current hypoallergenization techniques.

Soybean Allergens Affecting North American Patients Identified by 2D Gels and Mass Spectrometry

“…Currently, it is estimated that 2-6% of the North American population suffers from food allergies, and soybean is one of the eight foods that requires labeling in many countries (EU, Japan, Canada, and USA). Due to its widespread use in the food and beverage industry, soybean is often a "hidden ingredient," which adds to its significance as a food allergen (Zarkadas et al 1999;Hefle 2001;L'Hocine and Boye 2007).…”

Review Soybeans as bioreactors for biopharmaceuticals and industrial proteins

“…For the latter, the 15S fraction corresponds to 1% of the globulins, has a high molecular mass (700 kDa) and has an isoelectric point of 4.5. Furthermore, the known proteins in soybean seeds with high allergenic potential are mainly composed of a 34-kDa maturing seed protein (also known as P34, Gly m Bd 30 K or Gly m 1) (Sewekow et al, 2008), the 23-kDa protein Gly m Bd 28 K (Xiang et al, 2004), β-conglycinin (Krishnan et al, 2009), the glycinin Gly m 6 (Holzhauser et al, 2009), lectin andlypoxygenase (L'Hocine andBoye, 2007), and a Kunitztype protease inhibitor (Roychaudhuri et al, 2004). There are also some allergenic proteins in seed shell, such as Gly m 1.0101, Gly m 1.0102, Gly m 2, Gly m 3, and SAM 22 (Gly m 4).…”

Report on an investigation of asthma and respiratory symptoms among workers at a soy processing plant.

“…Soy is a known cause of food allergy and is considered one of eight major compounds responsible for 90% of IgE-mediated food allergy in childhood [Allen et al 2006;L'Hocine and Boye 2007]. At least 16 soy proteins have been identified as food allergens, some of which have immune cross-reactivity with proteins from other members of the legume family, such as peanut.…”