TY - JOUR
T1 - Molecular characterization, expression in Escherichia coli, and epitope analysis of a two EF-hand calcium-binding birch pollen allergen, Bet v 4
AU - Twardosz, Anna
AU - Hayek, Brigitte
AU - Seiberler, Susanne
AU - Vangelista, Luca
AU - Elfman, Lena
AU - Grönlund, Hans
AU - Kraft, Dietrich
AU - Valenta, Rudolf
PY - 1997/10/9
Y1 - 1997/10/9
N2 - Birch pollen belongs to the most potent elicitors of Type I allergic reactions in early spring. Using serum IgE from a birch pollen allergic patient, two cDNA clones (clone 6 and clone 13) were isolated from a birch pollen expression cDNA library constructed in phage λgt11. Clone 6 encoded a 9.3 kD two EF-hand calcium-binding protein, designated Bet v 4, with significant end to end sequence homology to EF-hand calcium-binding allergens from weed and grass pollen. Recombinant Bet v 4, expressed as β-galactosidase fusion protein, reacted with serum IgE from approximately 20% of pollen allergic individuals. Depletion of allergenbound calcium by EGTA treatment lead to a substantial reduction of IgE-binding to Bet v 4, indicating that protein-bound calcium is necessary for the maintenance of IgE-epitopes. The greatly reduced IgE-binding capacity of clone 13, a Bet v 4 fragment that lacked the 16 N-terminal amino acids, indicated that the N-terminus contributes significantly to the proteins IgE-binding capacity. By IgE-inhibition experiments it was demonstrated that recombinant Bet v 4 shared IgE-epitopes with natural Bet v 4 and a homologous timothy grass pollen allergen. Recombinant Bet v 4 may therefore be considered as a relevant crossreactive plant allergen, which may be used for diagnosis and treatment of patients suffering from multivalent plant allergies.
AB - Birch pollen belongs to the most potent elicitors of Type I allergic reactions in early spring. Using serum IgE from a birch pollen allergic patient, two cDNA clones (clone 6 and clone 13) were isolated from a birch pollen expression cDNA library constructed in phage λgt11. Clone 6 encoded a 9.3 kD two EF-hand calcium-binding protein, designated Bet v 4, with significant end to end sequence homology to EF-hand calcium-binding allergens from weed and grass pollen. Recombinant Bet v 4, expressed as β-galactosidase fusion protein, reacted with serum IgE from approximately 20% of pollen allergic individuals. Depletion of allergenbound calcium by EGTA treatment lead to a substantial reduction of IgE-binding to Bet v 4, indicating that protein-bound calcium is necessary for the maintenance of IgE-epitopes. The greatly reduced IgE-binding capacity of clone 13, a Bet v 4 fragment that lacked the 16 N-terminal amino acids, indicated that the N-terminus contributes significantly to the proteins IgE-binding capacity. By IgE-inhibition experiments it was demonstrated that recombinant Bet v 4 shared IgE-epitopes with natural Bet v 4 and a homologous timothy grass pollen allergen. Recombinant Bet v 4 may therefore be considered as a relevant crossreactive plant allergen, which may be used for diagnosis and treatment of patients suffering from multivalent plant allergies.
UR - http://www.scopus.com/inward/record.url?scp=0031561367&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031561367&partnerID=8YFLogxK
U2 - 10.1006/bbrc.1997.6860
DO - 10.1006/bbrc.1997.6860
M3 - Article
C2 - 9345295
AN - SCOPUS:0031561367
VL - 239
SP - 197
EP - 204
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 1
ER -