Shotgun proteomics and in silico analysis of potential allergens in mature seeds and sprouts of purple winged bean

Abstract

Winged bean (Psophocarpus tetragonolobus (L.) DC.) is a tropical legume crop found in Southeast Asian countries including Thailand. The mature seeds have high protein content and have been targeted as a protein source, and germination has been used to increase the value of nutrition. We used nanoLC/timsTOF Pro 2 combined with PEAKS® studio Xpro software to explore the proteomes of mature seeds and sprouts of purple winged bean. This study is the first report on the allergenic proteins in mature seeds and sprouts of purple winged bean. In silico analysis using Allergen Nomenclature search and the Allermatchtm program, 37 allergens were found. Conglutin beta 5 and late embryogenesis abundant protein (3 and D-29) were identified only in mature seeds, while 4 types of major pollen allergen Bet V, profilin and isoflavone reductase, were identified only in sprouts. Examples of allergens in both samples include basic 7S globulin, beta-conglycinin alpha/beta subunit (1,2), convicilin, defensin-like protein, 7 types of non-specific lipid-transfer protein, P24 oleosin isoform B. Since food allergy and airway allergy are found in sprouts, we used shotgun proteomics and in silico analysis for detecting the profiles of allergens. With regards to food safety, purple winged beans may also induce cross-reactivity in patients who are allergic to peanuts or other legumes. Therefore, identifying the proteomes and potential allergens in mature seeds and sprouts of purple winged beans could assist researchers in studying plant-based food safety.