Identification of an Abundant 56 kDa Protein Implicated in Food Allergy as Granule-Bound Starch Synthase

Abstract

Rice, the staple food of south and east Asian counties, is considered to be hypoallergenic. However, several clinical studies have documented rice-induced allergy in sensitive patients. Rice proteins with molecular weights of 14-16, 26, 33, and 56 kDa have been identified as allergens. Recently, it was documented that the 56 kDa rice allergen was responsible for rice-induced anaphylaxis. The 14-16 kDa allergens have been identified as α-amylase inhibitors; the 26 kDa protein has been identified as α-globulin; and the 33 kDa protein has been identified as glyoxalase I. However, the identity of the 56 kDa rice allergen has not yet been determined. In this study, we demonstrate that serum from patients allergic to maize shows IgE binding to a 56 kDa protein that was present in both maize and rice but not in the oil seeds soybean and peanut. The 56 kDa IgE-binding protein was abundant in the rice endosperm. We have purified this protein from rice endosperm and demonstrated its reactivity to IgE antibodies from the serum of maize-allergic patients. The purified protein was subjected to matrix-assisted laser desorption ionization-time of flight-tandem mass spectrometry analysis, resulting in identification of this rice allergen as granule-bound starch synthase, a product of the Waxy gene. Immunoblot analysis using protein extracts from a waxy mutant of rice revealed the absence of the 56 kDa IgE-binding protein. Our results demonstrate that the 56 kDa rice allergen is granule-bound starch synthase and raise the possibility of using waxy mutants of rice as a potential source of the hypoallergenic diet for patients sensitized to the 56 kDa rice allergen.

Identification of Genes Encoding Granule-Bound Starch Synthase Involved in Amylose Metabolism in Banana Fruit

“…2A and 2B). This molecular weight is similar to those GBSS proteins purified from rice (56 kDa) [20], maize (58 kDa) [21], and cowpea (58 kDa) [22]. SDS-PAGE and western blotting analyses indicated that banana GBSS proteins accumulated during the development of banana fruit and their levels decreased during fruit storage (Fig.2A and 2B).…”

Detection of IgE‐reactive proteins in hydrolysed dog foods

“…Four of the six identified proteins in this study have been described as human food allergens including maize/potato GBSS‐1, soybean glycinin (Gly m 6), soybean β‐conglycinin (Gly m 5), and potato aspartic protease inhibitor (Sol t 2) . These proteins have been defined as allergens by their IgE‐binding properties.…”

“…These proteins have been defined as allergens by their IgE‐binding properties. In a few cases, proteins were defined as allergens based on their capacity to induce histamine release from basophils, to trigger a positive skin test, or to reduce allergenicity of the food when the allergen is not expressed . Interestingly, soybean β‐conglycinin has also been described as an allergen in animals, including dogs, with the β chain being an important antigen across species .…”

Risk of developing major depression and bipolar disorder among adolescents with atopic diseases: A nationwide longitudinal study in Taiwan

“…The diagnostic codes used were based on the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM). The NHIRD has been used extensively in many epidemiologic studies in Taiwan (Wu et al, 2012;Bai et al, 2013;Chen et al, 2013aChen et al, , 2013bKrishnan and Chen, 2013;Shen et al, 2013).…”