2001 Fiscal Year Final Research Report Summary
Studies on allergens in fish and their processed products
| Project/Area Number |
11460097
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fisheries chemistry
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| Research Institution | Tokyo University of Fisheries |
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Principal Investigator |
SHIOMI Kazuo Tokyo University of Fisheries, Faculty of Fisheries, Professor, 水産学部, 教授 (90111690)
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| Project Period (FY) |
1999 – 2001
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| Keywords | Fish / Fish processed products / Allergen / Allergy / Parvalbumin / Collagen / ELISA / cDNA cloning |
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| Research Abstract |
1. Besides parvalbumin, the well-known fish allergen, a higher molecular weight allergen was newly detected in fish. The higher molecular weight allergen was purified from the bigeye tuna muscle and identified as collagen. Antigenic cross-reactivity was observed among fish collagens but not between collagens from fish and other animals such as mammals, crustaceans and mollusks.
2. When 20 sera from fish-allergic patients were evaluated for their IgE reactivity to parvalbumin and collagen purified from the bigeye tuna muscle by ELISA, as many as 7 sera reacted to collagen. Furthermore, IgE binding ability of collagen was almost the same as that of parvalbumin and the content of collagen in muscle was comparable to that of parvalbumin. These results suggest that collagen is an important fish allergen.
3. Heating of the homogenized fish muscle at 80ーC for 20 min was found to be most effective to simultaneously extract both parvalbumin and collagen. This extraction method is applicable to analysis of fish allergens by immunoblotting and diagnosis of fish allergy by RAST.
4. The CDNA library was constructed from the mackerel muscle and CDNA encoding parvalbumin was cloned DNA sequence analysis revealed that the mackerel parvalbumin is composed of 108 amino acid residues, being a b-form. Elucidation of IgE-binding epitopes of the mackerel parvalbumin is under progress using various synthetic peptides covering the total amino acid sequence.
5. Commercial fish meat paste products and their major raw material, surimi, were very low in allergenicity against parvalbumin-recognizing patients. In a model experiment using the walleye pollack muscle, parvalbumin was almost completely removed from the muscle during washing, suggesting that fish meat paste products made of fully washed surimi are hypoallergenic foods for parvalbumin-recognizing patients. The allergenicity (as to both parvalbumin and collagen) of fish extractives was also markedly reduced by digestion with proteases.
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