Cloning, expression, and primary structure of tropomyosin, the major heat-stable shrimp allergen (original) (raw)

1994, Journal of Allergy and Clinical Immunology

Shrimp is a common cause of seafood hypersensitivity. To study the mechanism of seafood hypersensitivity at the molecular level, we have determined the primary structure of the major heat-stable allergen of shrimp by cloning expression, nucleotide sequencing, and amino acid sequence determination of an IgE-reactive cDNA clone, Met e I, isolated from a Metapenaeus ensis expression library in Agt 11. We first constructed a cL)NA library from the shrimp M. ensis in ,@t 11. We then screened the library with sera JS-om patients with hypersensitivity reactions to shrimp and identified a positive IgE-reactive clone, designated as Met e I. This C-DNA was purified to homogeneity and subsequently expressed in the plasmid pGEX. Serum antibodies from patients with shrimp allergy demonstrated positive IgE reactivity by immunoblotting to a protein encoded by the clone Met e I, sera from nonallergic control subjects were not reactive. The nucleotide sequence of this (-DNA clone revealed an open reading frame of 281 amino acid residues, coding for a protein of 34 kd. Comparison of the Met e I amino acid sequence with the Genbank database showed that Met e I is highly homologous to multiple isofonns of tropomyosin.