Screening and in vitro Characterization of Allergic Proteins of Kiddi Shrimp (Parapenaeopsis stylifera) by Peptide Mass Fingerprinting

Abstract

Allergy associated with consumption of shellfishes is a major cause of food induced anaphylaxis. Kiddi shrimp (Parapenaeopsis stylifera), locally known as ‘karikkadi chemmeen’ is a highly preferred variety. Allergens in raw and cooked extracts were subjected
to identification by immunological methods using sera of shrimp allergic individuals and subjected to in vitro characterisation. Two protein fractions, namely hemocyanin (75 kDa) and tropomyosin (37 kDa), were identified as major allergens in the raw extract. In contrast. 37 kDa tropomyosin alone was identified as the major allergen in the cooked extract by 1D and 2DE immunoblotting. Both raw and cooked extracts exhibited higher IgE activity to sera from shrimp sensitive individuals. Tropomyosin of 37 kDa was recognized as the major allergen with the highest frequency of immunoreactivity. Mass spectrometry analysis of trypsin-digested tropomyosin
was carried out using MALDI-TOF. The peptide mass fingerprint analysis showed strong similarity to other crustacean species and exhibited within sequence variation compared to others.