Title
Influence of Thermal Treatment on the Characteristics of Major Oyster Allergen Cra g 1 (Tropomyosin)
Author
Lei Fang, Guoming Li, Ruizeng Gu, Muyi Cai, Jun Lu
Year
2018
Journal
Journal of the Science of Food and Agriculture
Abstract
Shellfish, including oysters, often cause allergic reactions in adults. Thermal treatment is one of the most common technologies to deal with seafood, which may affect biological properties. The aim of this work was to evaluate the impact of heating on conformation and potential allergenicity of oyster-derived tropomyosin (Cra g 1). SDS-PAGE showed that there was an apparent band at 35KD of raw tropomyosin after purification and more significant polymers appeared in heated protein. Interestingly, the obviously changes in the intensity of CD signal and ANS-binding fluorescence were observed especially in the case of roasted form, which was associated with an increase in antibody reactivity. The degree of IgE binding of this treatment was demonstrated in the order roasted>boiled > raw. Furthermore, sequence alignment and amino acid composition revealed that Cra g 1 shared relatively high homology to tropomyosins from other shellfish and was abundant in lysine that was apt to be modified by reducing sugars during heating. Heated Cra g 1 produces higher IgE reactivity than raw one, owing to denaturation and formation of polymers. These findings will benefit more diagnosis and management of potential allergenicity due to shellfish.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Protein folding, Thermal stability, Biochemistry, Food science