Allergen Data Collection - Update: Hazelnut (Corylus avellana)
Internet Symposium on Food Allergens 3(Suppl.1):1-22  (2001) [http://www.food-allergens.de]
6.3 Major Pollen Allergen (Cor a 1)

6.3.1 Molecular Biological Properties
 
Major Pollen Allergen References
Allergen Nomenclature Cor a 1.01 - Cor a 1.03 (1) Larsen & Lowenstein 2000
Isoallergens and Variants
4 isoallergens or variants by SDS/IEF-PAGE (1)
4 recombinant variants of Cor a 1.01 with aa identities of 96-99% (2)
2 additional isoallergens Cor a 1.02 and Cor a 1.03 (3)
(1) Rohac et al. 1991
(2) Breiteneder et al. 1993
(3) Hoffmann-Sommergruber et al. 1997
Molecular Mass 
17 kDa (1), (SDS-PAGE)
(1) Rohac et al. 1991
Isoelectric Point pI 5.0-5.8 (1)
(1) Rohac et al. 1991
Amino Acid Sequence,mRNA, and cDNA
Protein Cor a 1.0101 Cor a 1.0102 Cor a 1.0103 Cor a 1.0104
formerly Cor a 1/5 Cor a 1/6 Cor a 1/11 Cor a 1/16
SWISS-PROT: Q08407 Q08407 Q08407 Q08407
GenBank: X70999 X71000 X70997 X70998
PIR: S30053 S30054 S30055 S30056
Amino Acids 159 aa 159 aa 159 aa 159 aa
mRNA 619 bp 742 bp 655 bp 860 bp
cDNA        

Protein Cor a 1.0201 Cor a 1.0301
SWISS-PROT:    
GenBank: Z72439 Z72440
PIR:    
Amino Acids 160 aa 160 aa
mRNA    
cDNA 564 bp 577 bp
(1) Breiteneder et al. 1993
(2) Hoffmann-Sommergruber et al. 1997
recombinant Protein
Expression in Escherichia coli:
4 recombinant isoforms (1, 2)
(1) Breiteneder et al. 1993
(2) Schenk et al. 1994
Biological Function
Bet v 1 family of pathogenisis-related proteins (1)
(1) SWISS-PROT
Sequence Homology
a) of Cor a 1.01 isoforms to:
Birch pollen allergen Bet v 1: aa 71-73% identity, 80.5-83% similarity (1)
Alder pollen allergen Aln g 1: aa 75.5-76.7% identity, 83.6-85% similarity (1)
Hornbeam pollen allergen Car b 1: aa 83.6-89.9% identity, 89.3-95% similarity (1)
Apple allergen Mal d 1: aa 54% identity (2)
b) of Cor a 1.02 isoform to:
Cor a 1.01 isoforms: aa 73-75% identity, aa 85-87% similarity (3)
Birch pollen allergen Bet v 1: aa 80-85% identity, 89-93% similarity (3)
Apple allergen Mal d 1 isoforms: aa 56-66% identity, aa 72-81% similarity (3)
Celery allergen Api g 1: aa 40% identity, aa 61% similarity (3)
Carrot allergen Dau c 1 isoforms: aa 40% identity, aa 58% similarity (3)
c) of Cor a 1.03 isoform to:
Cor a 1.01 isoforms: aa 63-65% identity, aa 74-78% similarity (3)
Cor a 1.02 isoform: aa 71% identity (3)
Birch pollen allergen Bet v 1: aa 67-73% identity, 78-82% similarity (3)
Apple allergen Mal d 1 isoforms: aa 61-71% identity, aa 77-83% similarity (3)
Celery allergen Api g 1: aa 39% identity, aa 62% similarity (3)
Carrot allergen Dau c 1 isoforms: aa 37% identity, aa 58-60% similarity (3)
(1) Breiteneder et al. 1993
(2) Vieths et al. 1996
(3) BLAST at PIR

 6.3.2 Allergenic Properties
 
Major Pollen Allergen References
Frequency of Sensitization
IgE-binding to Cor a 1 in 100% of patients (1)
(1) see 5.1 Sensitization to Hazel Allergens
Allergenic Potencies
Differential IgE reactivity to 4 rCor a 1 isoforms by samples of 5 hazelpollen allergic patients (immunoblot) (1, 2)
(1) Breiteneder et al. 1993
(2) Schenk et al. 1994
Cross-reactivity
IgE- cross- reactive to rBet v 1 (1)
(1) see 7 Cross-Reactivities
T-Cell Proliferation / Epitopes
Stimulation of Bet v 1 specific T-cell clones with natural Cor a 1 (1)

Stimulation of Bet v1 specific T-cell clones from birch pollen and hazelpollen allergic patients with natural and recombinant Cor a 1 isoforms (2):
Isoform Positive Stimulation: 
nCor a 1 in 4/6 clones
rCor a 1/5 in 3/6 clones
rCor a 1/6 in 5/6 clones
rCor a 1/11 in 3/6 clones
rCor a 1/16 in 4/6 clones

Stimulation of Bet v1 specific T-cell clones from birch pollen and hazelpollen allergic patients with synthetic peptides according to internal sequences of rCor a 1 isoforms and rBet v 1 (2):
rCor a 1
5
6
11
16
rBet v 1
aa 12-23
+
+
+
-
+
aa 63-74 * (1)
+
+
+
+
+
aa 77-88
-
+
+
-
+
aa 97-108
-
+/-
-
+/-
+/-
aa 111-122
+
+
+
+
+
aa 144-155
+
+
+
+
+
* same sequence in all Cor a 1 isoforms

Amino acids critical for T-cell proliferation with synthetic peptides (2):
aa 12-23 position 14 (substitution Pro / Ser) 
aa 77-88 position 80 (substitution Lys / Thr)
aa 97-108 position 100 (substitution Ser / His)

(1) Ebner et al. 1993
(2) Schenk et al. 1994

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