Jug r 4, a legumin group food allergen from walnut (Juglans regia Cv. Chandler).
Allergy to walnut is the most frequently reported tree nut allergy in the United States. Walnut 2S albumin, a vicilin-like protein, and a lipid transfer protein allergen have previously been described. Our objective was to clone and express a cDNA encoding a legumin group protein, assess IgE-binding with sera from walnut allergic patients, and investigate cross-reactivity with selected nuts. Primers were used to obtain the cDNA by 5' and 3' rapid amplification of cDNA ends from walnut mRNA. The cDNA was subcloned into the pMAL-c2X vector and the recombinant fusion protein, named rJug r 4, was expressed in Escherichia coli. The obtained cDNA encoded a precursor protein with a predicted molecular weight of 58.1 kD, which showed significant sequence homology to hazelnut and cashew legumin allergens. Serum IgE from 21 of 37 (57%) patients bound the rJug r 4 fusion protein. In vitro cross-reactivity was demonstrated with hazelnut, cashew, and peanut protein extracts.
Wallowitz
Mikhael
M
Department of Internal Medicine, Division of Rheumatology, Allergy and Clinical Immunology, University of California-Davis School of Medicine, Davis, CA, USA.
Peterson
W Rich
WR
Uratsu
Sandie
S
Comstock
Sarah S
SS
Dandekar
Abhaya M
AM
Teuber
Suzanne S
SS
D000485:Allergens / Q000235:genetics*; D000595:Amino Acid Sequence; D000918:Antibody Specificity; D052179:Antigens, Plant / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli; D005512:Food Hypersensitivity / Q000276:immunology; D015870:Gene Expression; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000097:blood; D031324:Juglans / Q000276:immunology*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000276:immunology*; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins / Q000276:immunology; D016415:Sequence Alignment; D000097793:Legumins
D000485:Allergens; D052179:Antigens, Plant; D018076:DNA, Complementary; D007073:Immunoglobulin E; D010940:Plant Proteins; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D000097793:Legumins; C515172:Jug r 4 allergen