Effect of transglutaminase-catalyzed glycosylation on the allergenicity and conformational structure of shrimp (Metapenaeus ensis) tropomyosin.

Tropomyosin (TM), a myofibrillar protein, is a major allergen in shrimp. The aim of this study was to evaluate the effect of transglutaminase (TGase)-catalyzed glycosylation on the potential allergenicity and conformational structure of TM in Metapenaeus ensis. Results showed that glycosylation of TM induced unfolding of the primary protein structure followed by loss of the secondary structure. Cleavage of certain free amino groups was observed during TGase-catalyzed glycosylation. The glycosylation rate correlated with reaction temperature. Western blotting and indirect ELISA with TM-specific polyclonal antibodies from rabbit and sera from patients allergic to shrimp demonstrated that antigenicity and potential allergenicity of TM decreased, which correlated well with the conformational changes in its structure. Considering TGase is widely utilized in the food industry, these results indicate that TGase-catalyzed glycosylation has the potential to serve as a mild method for reducing the allergenicity of shrimp products.