title: Commercial processed soy-based food product contains glycated and glycoxidated lunasin proteoforms.
abstract: Nutraceuticals have been proposed to exert positive effects on human health and confer protection against many chronic diseases. A major bioactive component of soy-based foods is lunasin peptide, which has potential to exert a major impact on the health of human consumers worldwide, but the biochemical features of dietary lunasin still remain poorly characterized. In this study, lunasin was purified from a soy-based food product via strong anion exchange solid phase extraction and then subjected to top-down mass spectrometry analysis that revealed in detail the molecular diversity of lunasin in processed soybean foods. We detected multiple glycated proteoforms together with potentially toxic advanced glycation end products (AGEs) derived from lunasin. In both cases, modification sites were Lys24 and Lys29 located at the helical region that shows structural homology with a conserved region of chromatin-binding proteins. The identified post-translational modifications may have an important repercussion on lunasin epigenetic regulatory capacity. Taking together, our results demonstrate the importance of proper chemical characterization of commercial processed food products to assess their impact on consumer's health and risk of chronic diseases.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore.
authors.forename: Aida
authors.initials: A
authors.lastname: Serra
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore.
authors.forename: Xavier
authors.initials: X
authors.lastname: Gallart-Palau
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore.
authors.forename: Rachel Su-En
authors.initials: RS
authors.lastname: See-Toh
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore.
authors.forename: Xinya
authors.initials: X
authors.lastname: Hemu
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore.
authors.forename: James P
authors.initials: JP
authors.lastname: Tam
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore.
authors.forename: Siu Kwan
authors.initials: SK
authors.lastname: Sze
mesh_terms: D019587:Dietary Supplements / Q000032:analysis*; D005504:Food Analysis; D005511:Food Handling / Q000379:methods*; D006023:Glycoproteins / Q000032:analysis* / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D007474:Ion Exchange; D013058:Mass Spectrometry; D030262:Soybean Proteins / Q000737:chemistry / Q000302:isolation & purification*; D013025:Glycine max / Q000737:chemistry*
chemical_list: C120514:GM2S-1 protein, soybean; D006023:Glycoproteins; D030262:Soybean Proteins