cDNA cloning and primary structure of a white-face hornet venom allergen, antigen 5.

A major allergen of white-face hornet (Dolichovespula maculata) venom is antigen 5 (also designated Dol m V). We have determined the primary structures of two forms of this protein by cDNA and protein sequencings. These two forms with 204 and 205 amino acid residues differ in 23% of their sequences but they are antigenically similar. Both forms have sequence similarity with a pathogenesis-related protein of tobacco leaf. In a 130-residue overlap of these proteins, 35-39 residues were identical. Hornet antigen 5 cDNAs were isolated from an expression library in lambda gt11 phage using antibody probes. Several of the cDNAs were not full length, but the fusion fragments expressed were immunoreactive. These results suggest that antigenic determinants of the sequential type are distributed throughout the entire molecule of antigen 5. After subcloning, antigen 5 was also expressed in pKK233-2 plasmid.