title: Recombinant tropomyosin from Penaeus aztecus (rPen a 1) for measurement of specific immunoglobulin E antibodies relevant in food allergy to crustaceans and other invertebrates.
abstract: Immunoglobulin E (IgE)-mediated food allergy to crustaceans and mollusks is relatively common and affected individuals typically react to a range of different species. The only known major allergen of shrimp was first described over 20 years ago and later identified as the muscle protein tropomyosin. This protein may be useful as a defined and relevant diagnostic marker for allergic sensitization to invertebrate foods. In order to generate an assay reagent suitable for this purpose, tropomyosin from the shrimp Penaeus aztecus (Pen a 1) was produced as a recombinant protein in Escherichia coli and characterized with respect to IgE antibody binding properties in comparison to natural shrimp tropomyosin. Hexahistidine-tagged rPen a 1 accumulated as a predominantly soluble protein in the E. coli expression host and a two-step chromatographic procedure provided a high yield of pure and homogeneous protein. rPen a 1 displayed chromatographic and folding characteristics similar to those of purified natural shrimp tropomyosin. Serum preincubation with serial protein dilutions revealed similar capacity of recombinant and natural tropomyosin to compete with immobilized shrimp extract for IgE binding. rPen a 1 was further shown to extensively and specifically compete for IgE binding to extracts of other crustacean species, house dust mite and German cockroach.
authors.affiliation: Pharmacia Diagnostics AB, Uppsala, Sweden.
authors.forename: Asa Marknell
authors.initials: AM
authors.lastname: DeWitt
authors.forename: Lars
authors.initials: L
authors.lastname: Mattsson
authors.forename: Iris
authors.initials: I
authors.lastname: Lauer
authors.forename: Gerald
authors.initials: G
authors.lastname: Reese
authors.forename: Jonas
authors.initials: J
authors.lastname: Lidholm
mesh_terms: D000485:Allergens / Q000276:immunology*; D000918:Antibody Specificity; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005512:Food Hypersensitivity / Q000276:immunology*; D015870:Gene Expression; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis* / Q000097:blood; D033561:Penaeidae / Q000737:chemistry*; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification; D012758:Shellfish; D013045:Species Specificity; D014335:Tropomyosin / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000485:Allergens; D011994:Recombinant Proteins; D014335:Tropomyosin; D007073:Immunoglobulin E