ALLERGENS IN HYMENOPTERA VENOM .XXVI. THE COMPLETE AMINO-ACID-SEQUENCES OF 2 VESPID VENOM PHOSPHOLIPASES

The 2 major allergenic proteins in vespid venoms are antigen 5s and phospholipases (PLs). Vespid PLs have a molecular weight of about 34,000 and have been previously shown to have an A(1)B specificity, unlike the A(2) specificity of bee PLs. The complete amino acid sequences of the venom PL from the yellow jacket, Vespula maculifrons, and the more acidic isoenzyme from the white faced hornet, Dolichovespula maculata, have been determined by sequencing overlapping peptides isolated from enzyme and chemical digests of the proteins. Ves m 1 is composed of 300 amino acids, with variants found at 3 positions. Dol m 1.02 is composed of 303 amino acids with variants at 2 positions. Comparison with the sequence of Dol m 1.01 determined by cDNA sequencing gave 66.7% identity with Dol m 1.01 with almost all variation in the first 131 positions. Ves m 1 showed 69% identity with Dol m 1.01 and 38.7% with Dol m 1.02. Comparison of the PL sequences with the Protein Identification Resource data base showed many similarities with the lipase family, but very little relationship to known PLs. The amount of structural similarity between Dol m 1 and Ves m 1 is similar to that found among antigen 5 molecules of different genera, and is sufficient to account for antigenic cross-reactivity. There appear to be a number of highly conserved regions of the PL molecules, especially in the C-terminal 168 residues. These regions may from common epitopes found in several species and genera of vespids. Antibodies against these common epitopes will not be able to distinguish among PLs from various vespids. The finding of 2 significantly different sequences for Dol m 1 is parallel to the finding for Dol m 5.