Identification and characterization of Che a 1 allergen from Chenopodium album pollen.
BACKGROUND
Pollinosis to Chenopodium album has been reported, but no data are available on its allergenic proteins.


METHODS
An allergen from C. album pollen has been isolated by means of gel permeation and reverse-phase high-performance liquid chromatography. Molecular characterization was achieved by concanavalin A reaction, mass spectrometry, Edman degradation and cDNA sequence. Antigenic analyses were performed by immunoblotting, ELISA, and ELISA inhibition, using sera from allergic patients, two Ole e 1-specific monoclonal antibodies and an Ole e 1-specific polyclonal antiserum.


RESULTS
The isolated allergen, Che a 1, is a glycoprotein of molecular mass 17.088 kD and 143 amino acid residues, whose sequence exhibits 27-45% identity with known members of the Ole e 1-like protein family. 77% of sera from patients allergic to chenopod pollen were reactive to Che a 1. No correlation was found between the IgE reactivities to Che a 1 and Ole e 1, the major allergens from olive pollen, and both allergens display low, although detectable, IgE and IgG cross-reactivities.


CONCLUSIONS
Che a 1, a relevant allergen from chenopod pollen, is structurally related to the Ole e 1-like protein family, but exhibits significant differences on its polypeptide sequence that could explain its different antigenic behavior and limited cross-reactivity.
Barderas
Rodrigo
R
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain.
Villalba
Mayte
M
Lombardero
Manuel
M
Rodríguez
Rosalía
R
D000485:Allergens / Q000009:adverse effects / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D052179:Antigens, Plant; D001483:Base Sequence; D027463:Chenopodium album / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D003429:Cross Reactions; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000276:immunology; D011058:Pollen / Q000009:adverse effects / Q000737:chemistry* / Q000276:immunology*; D011817:Rabbits; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology; D017422:Sequence Analysis, DNA
D000485:Allergens; D052179:Antigens, Plant; C451660:Che a 1 allergen; D018076:DNA, Complementary; C081946:Ole e I protein, Olea europaea; D010940:Plant Proteins; D007073:Immunoglobulin E