Cloning, expression, and primary structure of Metapenaeus ensis tropomyosin, the major heat-stable shrimp allergen.
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 lambda gt 11. We first constructed a cDNA library from the shrimp M. ensis in lambda gt 11. We then screened the library with sera from patients with hypersensitivity reactions to shrimp and identified a positive IgE-reactive clone, designated as Met e I. This cDNA 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 cDNA 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 isoforms of tropomyosin.
Division of Rheumatology, Allergy and Clinical Immunology, School of Medicine, University of California Davis.
P S
PS
Leung
K H
KH
Chu
W K
WK
Chow
A
A
Ansari
C I
CI
Bandea
H S
HS
Kwan
S M
SM
Nagy
M E
ME
Gershwin
D000485:Allergens / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004355:Drug Stability; D005512:Food Hypersensitivity / Q000097:blood; D015723:Gene Library; D006358:Hot Temperature; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins; D014335:Tropomyosin / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*
D000485:Allergens; D018076:DNA, Complementary; D011994:Recombinant Proteins; D014335:Tropomyosin; D007073:Immunoglobulin E