CLONING OF 2 DISTINCT CDNAS ENCODING PARVALBUMIN, THE MAJOR ALLERGEN OF ATLANTIC SALMON (SALMO-SALAR)

Allergy to fish is common in Northern Europe. Variable reactions to di fferent fish species are usually experienced among fish allergic patie nts. The allergens of cod fish and particularly the major allergen par valbumin beta (Gadus callarias) have been extensively studied in Norwa y. In the present communication, the white muscle parvalbumin was simi larly found to be a major allergen in Atlantic salmon (Salmo salar, Sa l s1). A purified salmon parvalbumin was obtained by anion exchange ch romatography, gel filtration chromatography (GFC) and high-performance liquid chromatography (HPLC) of the muscle extracts. The antigenicity and allergenicity of salmon parvalbumin were confirmed using various immunologic and electrophoretic techniques. The protein is representat ive for several isoallergens judged by the amino acid (AA) sequence va riance at certain sites in the AA sequence of CNBr cleavage peptides. Using sera from patients with cod and salmon allergy Sal s1 was demons trated to be the major allergen of Atlantic salmon, as judged by RAST- and ELISA-inhibitions and crossed radioimmunoelectrophoresis (CRIE) t echniques. The protein was also demonstrated to be antigenic by the us e of polyclonal cod and salmon antibodies in Ige ELISA and immunoelect rophoretic methods. Cloning of parvalbumin cDNA from Atlantic salmon w as performed based on an alignment of parvalbumin AA sequences from ot her species. A probe was generated by PCR and used for screening a sal mon muscle cDNA-library. Subcloning and sequencing of two hybridizing clones revealed transcripts from two different parvalbumin genes. The translated sequences of both clones belong to the beta-lineage of parv albumins and include the entire coding region.