Characterization of Major and Minor Allergens of Sharp-rostrum Prawn

Seafood allergy seems to be increasing in Asia as well as worldwide. Characterization of seafood allergens is important in order to understand the immune response to these allergens. To date, several prawn allergens have been identified including tropomyosin, arginine kinase, sarcoplasmic calcium-binding protein (SCP) and myosin light-chain (MLC). Objective: The aim of this study was to identify the major and minor allergens of Parapenaeopsishardwickii (sharp-rostrum prawn), the most commonly consumed prawn in Malaysia. Methods: The raw and cooked extracts were prepared from the prawn shell and meat. Both extracts were fractionated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), transferred to nitrocellulose membranes and analyzed by immunoblotting using sera from patients with allergy to prawns. Results: In SDS-PAGE, the raw extract exhibited more protein bands than the cooked extract, ranging from molecular weights of 15 to 200 kDa. Immunoblotting of raw extract demonstrated numerous IgE-binding bands, whereas the cooked extract had fewer IgE-binding bands. The 36 kDa heat-resistant protein constitutes a major allergen, while several other heat-sensitive and heat-resistant proteins were recognized as potential minor allergens. Conclusion: A heat-stable band of 36 kDa was identified as the major allergen of this species of prawn. This protein is believed to be tropomyosin, a well-documented major heat-stable allergen in prawn.