PURIFICATION AND CHARACTERIZATION OF 2 FORMS OF ANTIGEN-5 FROM POLYBIA-SCUTELLARIS VENOM

Two polypeptides from the venom of Polybia scutellaris were purified t o homogeneity by RP-HPLC. They differ very slightly in mel, wt (both a re about 23,000) and hydrophobicity, and have isoelectric points great er than 9. Amino acid analyses show close similarity between them and with antigen 5 of vespids from different species. The two polypeptides have an identical N-terminal sequence (18 amino acids) which shows a high degree of homology with those of other vespids. Owing to the fact that the venom of this species is non-allergenic, the data for the me l, wt, isoelectric point, amino acid composition and N-terminal sequen ce allow us to identify the isolated polypeptides as two forms of anti gen 5. Amino acids at positions 5 and 11 in P. scutellaris antigen 5 d iffer from those of the previously known sequences for antigen 5, sugg esting that one or other might be responsible for the lack of allergen icity of the P. scutellaris venom.