Investigation of conformational and epitope alterations of shrimp tropomyosin under α-dicarbonyl glycation and conformation-allergenicity relationship

The incidence of shrimp-induced food allergy is increasing yearly. Glycation has been reported to reduce shrimp tropomyosin (TM) allergenicity, and how advanced glycation end products (AGEs) impact TM allergenicity has garnered worldwide attention. This work investigated the conformational and epitope alterations of TM under α-dicarbonyl compounds (glyoxal (GO), methylglyoxal (MGO), butanedione (BU)) glycation and conformation-allergenicity relationship. As the results, α-dicarbonyl compounds glycation induced high glycation and TM conformational alterations. AGEs glycation sites on TM epitopes were identified by HPLC-MS/MS, with epitope destruction rates of 62.5 %, 50 % and 62.5 % for GO-TM, MGO-TM and BU-TM, respectively. Immunological results revealed TM glycated by α-dicarbonyls compounds performed weaker IgE binding by 33.38–33.86 %, while GO and MGO reduced IgG binding by 63.60 % and 77.72 %, respectively, suggesting α-dicarbonyls compounds reduced TM allergenicity via AGEs-induced epitope loss and conformational changes. This investigation could provide novel insights into how α-dicarbonyls compounds reduce TM allergenicity and prevent shrimp-induced allergy.