Identification, cloning, and recombinant expression of procalin, a major triatomine allergen

Among the most frequent anaphylactic reactions to insects are those attribu ted to reduviid bugs. We report the purification and identification of the major salivary allergen of these insects. This 20-kDa protein (procalin) is a member of the lipocalin family, which includes salivary allergens from o ther invertebrates and mammals. An expression system capable of producing r eagent quantities of recombinant allergen was developed in Saccharomyces ce revisiae. Antisera produced against recombinant protein cross-reacts with E LISA with salivary allergen. Recombinant Ag is also shown to react with ser a from an allergic patient but not with control sera. By immunolocalization , the source of the salivary Ag is the salivary gland epithelium and its se cretions.