Identification of collagen as a new fish allergen

This study was intended to identify a high molecular weight allergen that had been detected in fish. Analyses by ELISA of five protein fractions prepared from bigeye tuna muscle showed that the high molecular weight allergen was contained in the myostromal protein fraction. Based on the results of SDS-PAGE, immunoblotting and amino acid analysis of the myostromal protein fraction, the high molecular weight allergen was judged to be collagen. Five of the eight patient sera used were found to react to the bigeye tuna collagen. In competitive ELISA inhibition experiments, the bigeye tuna collagen almost completely inhibited the IgE reactivity to the heated extracts from five species of fish, suggesting that collagen is commonly allergic regardless of fish species. However, no antigenic cross-reactivity was observed between collagens from fish and other animals.