Use of monoclonal antibodies to isolate and characterize Cyn d I, the major allergen of Bermuda grass pollen.
BACKGROUND
Cyn d I has been found to be the major allergen of Bermuda grass (Cynodon dactylon) pollen, but its exact nature remains to be clarified.


METHODS
Cyn d I, the major allergen of Bermuda grass (Cynodon dactylon) pollen, was purified by monoclonal antibody (MoAb) affinity chromatography, and its biochemical and immunologic properties were characterized. Anti-Cyn d I MoAb 4-37, which recognizes all of the isoallergens of Cyn d I, was chosen as the immunosorbent.


RESULTS
The purified protein has an amino acid composition similar to that of the group I allergens of other grass pollens. It appears as a single 34 kd band or as a mixture of 34 and 29 kd polypeptides in sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis. The hydrophobicity of these two polypeptides is similar because they have the same retention time on a C18 reverse-phase column when a trifluoroacetic acid/H2O/CH3CN buffer system is used. The N-terminal amino acid sequence of the 34 kd component has a 60% homology with residues of 1-25 of Lol p I, whereas that of the 29 kd component has a 68% homology with residues 31-68 of Lol p I. In addition, this 29 kd polypeptide can be recognized by another anti-Cyn d I MoAb 1-61.


CONCLUSIONS
These results suggest that the 29 kd component is derived from Cyn d I. In spite of the similarity in the amino acid composition between Cyn d I and group I allergens of other grass pollens, none of our four anti-Cyn d I MoAbs cross-reacted with 10 other grass pollens tested, including ryegrass pollen. Despite biochemical similarity with other group I allergens, the B-cell epitopes on Cyn d I are different from those on other grass pollens.
Han
S H
SH
Institute of Microbiology and Immunology, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China.
Chang
Z N
ZN
Chi
C W
CW
Perng
H J
HJ
Liu
C C
CC
Tsai
J J
JJ
Tam
M F
MF
D000485:Allergens / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000302:isolation & purification*; D006109:Poaceae; D011058:Pollen; D011863:Radioimmunoassay
D000485:Allergens; D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; C071778:CYND1 protein, Cynodon dactylon; D010940:Plant Proteins