Peptide mapping analysis of group I allergens of grass pollens

Group I allergens, from eight different clinically important grass pollens of the Pooideae (rye-grass, canary, Kentucky bluegrass, orchard and timothy), Chloridoideae (Bermuda grass) and Panicoideae (Johnson grass, maize) were isolated by sodium dodecyl sulphate polyacrylamide gel electrophoresis and subjected to limited partial proteolysis and cyanogen bromide cleavage. The generated digests were visualised on gels by silver staining. Replicate gels were blotted and screened with Lolp I-specific mAb FMC A1 and IgE binding to an allergic human serum pool, to determine the degree of antigenic and IgE-binding similarities, respectively. The highest antigenic and IgE-binding similarities were between orchard and rye-grass pollens, both in the same tribe Poeae, and among the closely related grass genera. No peptide mapping of major grass pollen allergens has previously been undertaken. This study proves peptide mapping is a powerful method for the preliminary identification and internal amino acid microsequencing of common antigenic and IgE-binding determinants of allergens, providing information that is useful in the development of reagents for the treatment of grass-pollen-associated allergies.