Molecular characterization of recombinant T1, a non-allergenic periwinkle (Catharanthus roseus) protein, with sequence similarity to the Bet v 1 plant allergen family.
More than 25% of the population suffer from Type I allergy, an IgE-mediated hypersensitivity disease. Allergens with homology to the major birch ( Betula verrucosa ) pollen allergen, Bet v 1, belong to the most potent elicitors of IgE-mediated allergies. T1, a cytokinin-inducible cytoplasmic periwinkle ( Catharanthus roseus ) protein, with significant sequence similarity to members of the Bet v 1 plant allergen family, was expressed in Escherichia coli. Recombinant T1 (rT1) did not react with IgE antibodies from allergic patients, and failed to induce basophil histamine release and immediate-type skin reactions in Bet v 1-allergic patients. Antibodies raised against purified rT1 could be used for in situ localization of natural T1 by immunogold electron microscopy, but did not cross-react with most of the Bet v 1-related allergens. CD analysis showed significant differences regarding secondary structure and thermal denaturation behaviour between rT1 and recombinant Bet v 1, suggesting that these structural differences are responsible for the different allergenicity of the proteins. T1 represents a non-allergenic member of the Bet v 1 family that may be used to study structural requirements of allergenicity and to engineer hypo-allergenic plants by replacing Bet v 1-related allergens for primary prevention of allergy.
Laffer
Sylvia
S
Department of Pathophysiology, University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
Hamdi
Said
S
Lupinek
Christian
C
Sperr
Wolfgang R
WR
Valent
Peter
P
Verdino
Petra
P
Keller
Walter
W
Grote
Monika
M
Hoffmann-Sommergruber
Karin
K
Scheiner
Otto
O
Kraft
Dietrich
D
Rideau
Marc
M
Valenta
Rudolf
R
D000485:Allergens / Q000737:chemistry* / Q000235:genetics; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D001483:Base Sequence; D029662:Betula / Q000737:chemistry / Q000276:immunology; D030008:Catharanthus / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D002942:Circular Dichroism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics; D017510:Protein Folding; D011994:Recombinant Proteins / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D015183:Restriction Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012882:Skin Tests; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; D011994:Recombinant Proteins