Tropomyosin, the major tropical oyster Crassostrea belcheri allergen and effect of cooking on its allergenicity
نویسندگان
چکیده
BACKGROUND Many types of shellfish including oysters are sometime cooked before ingestion and it has been demonstrated that cooking may affect the allergenicity of food. Therefore, the aim of our present study is to identify major and minor allergens of tropical oyster (Crassostrea belcheri) and to investigate the effect of different cooking processing on the allergenicity of this oyster. METHODS Raw, boiled, fried and roasted extracts of oyster were prepared. Protein profiles were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Major and minor allergens and allergenicity patterns of all extracts were then determined by immunoblotting with sera from patients with positive skin prick tests (SPT) to the raw oyster extract. Mass-spectrometry was used to identify the major allergenic proteins of this oyster. RESULTS SDS-PAGE of the raw extract showed 15 protein bands (20-180 kDa). In contrast, smaller numbers of protein bands were demonstrated in the boiled extract, those ranging between 40-42 and 55-150 kDa were denatured, whereas the protein profiles were altered to a similar degree by frying or roasting. The 37 kDa proteins had the highest frequency of IgE-binding (95 %), thus identified as the major allergen of this tropical oyster. Other minor IgE-binding proteins were observed at various molecular weights. Immunoblot of raw extract yielded 11 IgE-binding proteins. The cooked extracts showed only a single IgE-binding protein at 37 kDa. Mass spectrometry analysis of the 37 kDa major allergen identified this spot as tropomyosin. CONCLUSIONS Cooked extracts produce lower IgE-binding than raw extract, which suggest that thermal treatment can be used as a tool in attempting to reduce oyster allergenicity by reducing the number of IgE-reactive bands. The degree of allergenicity of this oyster was demonstrated in the order raw > boiled > fried ≈ roasted. A heat-resistent 37 kDa protein, corresponding to tropomyosin, was identified as the major allergen of this tropical oyster.
منابع مشابه
Tropomyosin and Actin Identified as Major Allergens of the Carpet Clam (Paphia textile) and the Effect of Cooking on Their Allergenicity
OBJECTIVES To identify the major allergenic proteins of clam (Paphia textile) and to investigate the effect of different cooking methods on the allergenicity of these identified proteins. METHODS Clam protein extracts were separated by denaturing polyacrylamide gel electrophoresis. IgE reactive proteins were then analyzed by immunoblotting with sera from patients with positive skin prick test...
متن کاملDevelopment of Crassostrea belcheri (Sowerby, 1871), Crassostrea iredalei (Faustino, 1932) and inter-specific cross spats at different salinity
Hybrids between Crassostrea belcheri (CB) and C. iredalei (CI) were produce to evaluate their aquaculture potential. These inter and intra-specific crosses consisted of CB♀XCB♂, CI♀XCI♂, CB♀XCI♂ and CI♀XCB♂. To evaluate their environmental preferences, the spats of 40 day-old were cultured in 10, 20 and 30 ppt for 30 days. Hybrids showed significantly higher (p<0.05) shell increment when cultur...
متن کاملDetection of hepatitis A virus and bacterial contamination in raw oysters in Thailand.
This study was conducted to determine the presence of hepatitis A virus (HAV) in raw oysters (Crassostrea belcheri) using a virus concentration method and reverse transcription-nested polymerase chain reaction (RT-nested PCR). A total of 220 oyster samples were collected from oyster farms and local markets in Thailand. HAV was found in three oyster samples. Nested PCR products of HAV detected i...
متن کاملIdentification of tropomyosin as major allergen of white squid (Loligo edulis) by two-dimensional immunoblotting and mass spectrometry.
IgE-mediated allergic reaction to squid is one of the most frequent molluscan shellfish allergies. Previously, we have detected a 36 kDa protein as the major allergen of Loligo edulis (white squid) by immunoblotting using sera from patients with squid allergy. The aim of this present study was to further identify this major allergen using a proteomics approach. The major allergen was identified...
متن کاملCharacterization of Antibacterial Protein from Hemolymph of Oyster Crassostrea belcheri
The hemolymph of oyster Crassostrea belcheri was found to possess significant antibacterial activity against Vibrio harveyi, V. vulnificus and V. cholerae. Hemolymph was partially purified by gel filtration chromatography on Sephacryl S-200 and fractioned into four parts: P1, P2, P3 and P4. The P3 showed the highest antibacterial activity against V. parahaemolyticus, V. cholerae, V. alginolytic...
متن کامل