Characterization of Major and Minor Allergens of Sharp-Rostrum Prawn (Parapenaeopsishardwickii)

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.