Expression of Jug r 1, the 2S albumin allergen from walnut (Juglans regia), as a correctly folded and functional recombinant protein.
Jug r 1, the 2S albumin allergen from walnut, was isolated from ripe nuts as a native allergen and expressed in Escherichia coli using the Gateway technology as a recombinant allergen. The recombinant Jug r 1 (15 kDa) differs from the native allergen by the absence of cleavage of the polypeptide chain in two covalently associated light (3.5 kDa) and heavy (8 kDa) chains. Recombinant rJug r 1 adopts the canonical alpha-helical fold of plant 2S albumins as checked on CD spectra. Four IgE-binding epitopic stretches were identified along the amino acid sequence of Jug r 1 and localized on the molecular surface of the modeled allergen. Both native and recombinant allergens exhibit similar IgE-binding activity and similarly trigger the degranulation of a FcepsilonRI-expressing rat basophilic leukaemia cell line previously treated by IgE-containing sera. Native Jug r 1 resists to heat denaturation and to the proteolytic attack of trypsin and chymotrypsin but is readily hydrolyzed in the presence of pepsin at acidic pH after 1 h of incubation at 37 degrees C in vitro. Recombinant Jug r 1 could be used for a component-resolved diagnosis of food-allergy.
Sordet
Camille
C
UMR Université Paul Sabatier-CNRS 5546, Pôle de Biotechnologie végétale, 24 Chemin de Borde Rouge, 31326 Castanet Tolosan, France.
Culerrier
Raphaël
R
Granier
Claude
C
Rancé
Fabienne
F
Didier
Alain
A
Barre
Annick
A
Rougé
Pierre
P
D055516:2S Albumins, Plant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D052179:Antigens, Plant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D045744:Cell Line, Tumor; D000939:Epitopes / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007073:Immunoglobulin E / Q000378:metabolism; D031324:Juglans / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D055516:2S Albumins, Plant; D052179:Antigens, Plant; D000939:Epitopes; D011994:Recombinant Proteins; D007073:Immunoglobulin E