Using monoclonal antibodies to characterize a sequential epitope on the group I allergen of Bermuda grass pollen.
BACKGROUND
Cyn d 1, the group I allergen of Bermuda grass pollen, had been purified and characterized.


METHODS
A sequential B cell epitope on Cyn d 1 was studied with monoclonal antibodies (MoAbs). Cyn d 1 was cleaved by Achromobacter protease I into fragments, and the resulting peptides were fractionated on reversed-phase columns before being reacted with anti-Cyn d 1 MoAbs in a radioimmunoassay. A Cyn d 1 fragment recognized by its MoAb was selected for Edman degradation. A synthetic peptide was constructed according to the determined sequence.


RESULTS
The epitope on Cyn d 1 recognized by MoAb 18-53 was found to be conformation independent, since its activity was not changed after sodium periodate, guanidine or urea treatment. The enzyme-cleaved fragment containing this epitope was determined to be DVDKPPFDGMTACGNEPIF which corresponds to the N-terminal 46-64 residues of Cyn d 1. The presence of this sequence in the epitope recognized by MoAb 18-53 was demonstrated by enzyme immunoassay and further confirmed by inhibition of binding enzyme immunoassay with synthetic peptides. Some cross-reactivity with the N-terminal 45-63 residues of Lol p 1 was also found.


CONCLUSIONS
The primary structure of a sequential epitope on Cyn d 1 was determined, and its activity was confirmed with peptides synthesized according to the determined sequence.
Chang
Z N
ZN
Faculty of Medical Technology, Research Center for Immunology, National Yang-Ming University, Taipei, Taiwan, Republic of China.
Tam
M F
MF
Liu
C C
CC
Chi
C W
CW
Peng
H J
HJ
Han
S H
SH
D000485:Allergens / Q000737:chemistry / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D052179:Antigens, Plant; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions / Q000276:immunology; D000939:Epitopes / Q000032:analysis*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology*; D006109:Poaceae / Q000276:immunology*; D011058:Pollen / Q000276:immunology*; D011863:Radioimmunoassay; D017421:Sequence Analysis
D000485:Allergens; D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; C071778:CYND1 protein, Cynodon dactylon; D000939:Epitopes; D010446:Peptide Fragments; D010940:Plant Proteins