N-terminal sequences of high molecular weight allergens from celery tuber.
BACKGROUND
Celery tuber is an important source of food allergens. Low molecular weight celery allergens were identified as homologues of Bet v 1 and profilin. Little is known about the relevant allergens with molecular weights between 45 and 60 kDa, which cross-react with other plant food and pollen allergens.


OBJECTIVE
The aim of this study was to isolate cross-reactive, high molecular weight allergens from celery and to characterize them by N-terminal sequencing.


METHODS
High molecular weight allergens of celery were identified by immunoglobulin (Ig) E immunoblotting with patients' sera, and the IgE-binding patterns were compared with those of the monoclonal antibirch pollen antibody BIP3, as well as of a polyclonal rabbit anti-Art v 1 antiserum. Two independent methods, elution from preparative SDS-PAGE or anion exchange chromatography, were used to purify the IgE-binding celery proteins of interest. The isolated proteins were examined by N-terminal sequencing and IgE-immunoblots.


RESULTS
Celery allergens with molecular masses of 55, 58 and 63 kDa, which were also recognized by the monoclonal BIP3 antibody and a polyclonal anti-Art v 1 antiserum, were isolated. The 63-kDa allergen was N-terminally blocked. The 55- and 58-kDa compounds yielded the same N-terminus, which showed no homology to known proteins in the databases.


CONCLUSIONS
The combination of two independent protein separation techniques, immunoblotting and N-terminal sequencing, identified an N-terminus of two allergens in the 60-kDa molecular weight region. Our data will be helpful for the definite molecular characterization of these important cross-reactive molecules.
Ganglberger
E
E
Department of General & Experimental Pathology, AKH, University of Vienna, Austria.
Radauer
C
C
Grimm
R
R
Hoffmann-Sommergruber
K
K
Breiteneder
H
H
Scheiner
O
O
Jensen-Jarolim
E
E
D000485:Allergens / Q000276:immunology*; D000818:Animals; D052179:Antigens, Plant; D019661:Apiaceae / Q000276:immunology*; D003285:Contractile Proteins; D005512:Food Hypersensitivity; D006801:Humans; D008840:Microfilament Proteins / Q000276:immunology*; D010940:Plant Proteins / Q000276:immunology*; D051304:Profilins; D011817:Rabbits
D000485:Allergens; D052179:Antigens, Plant; D003285:Contractile Proteins; D008840:Microfilament Proteins; D010940:Plant Proteins; D051304:Profilins; C061312:Bet v 1 allergen, Betula