Wheat flour peroxidase is a prominent allergen associated with baker's asthma.
BACKGROUND
Putative wheat allergens with molecular sizes around 35kDa have been repeatedly detected in immunoblots using sera from patients with baker's asthma. However, none of these allergens had been previously isolated.


OBJECTIVE
To purify and characterize a major component of the 35 kDa allergenic band which seems to be present in flour from diploid, tetraploid (pasta) and hexaploid (bread) wheats.


METHODS
Gel-filtration chromatography followed by RP-HPLC have allowed the purification of a new wheat allergen. Immunodetection with sera from allergic patients and with a specific serum for asparagine-linked complex glycans, as well as amino acid sequencing, were used to identify the isolated protein.


RESULTS
A 36 kDa allergen has been purified from wheat flour. Its N-terminal and internal sequences, N-linked glycans, and enzymatic activity indicated that this allergen is a seed-specific peroxidase. Sera from six out of 10 patients hypersensitive to wheat flour displayed positive reactions when assayed against the purified dot-blotted allergen.


CONCLUSIONS
Seed-specific peroxidases from cereals (flours) seem to be important allergens in hypersensitive diseases associated with the manipulation of these plant materials. A new enzyme has thus been involved in IgE-mediated diseases.
Sánchez-Monge
R
R
Departamento de Biotecnología, E.T.S. Ingenieros Agrónomos, UPM, Madrid, Spain.
García-Casado
G
G
López-Otín
C
C
Armentia
A
A
Salcedo
G
G
D000485:Allergens / Q000276:immunology / Q000302:isolation & purification; D000595:Amino Acid Sequence; D001249:Asthma / Q000276:immunology*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis / Q000276:immunology; D008969:Molecular Sequence Data; D009784:Occupational Diseases / Q000276:immunology*; D010544:Peroxidases / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D011134:Polysaccharides / Q000276:immunology; D016415:Sequence Alignment; D017421:Sequence Analysis; D014908:Triticum / Q000276:immunology*
D000485:Allergens; D011134:Polysaccharides; D007073:Immunoglobulin E; D010544:Peroxidases