Expressions of recombinant venom allergen, antigen 5 of yellowjacket (Vespula vulgaris) and paper wasp (Polistes annularis), in bacteria or yeast

Antigen 5 is a major allergen of vespid venom. It has partial sequence iden tity with proteins from diverse sources. The biologic function of Ag 5 and its related proteins is not known. We are interested in the expression of A g 5 with the native conformation of the natural protein since its B cell ep itopes are mainly of the discontinuous type. When expressed in bacteria, re combinant Ag 5 formed an insoluble intracellular product, and it did not tr anslocate from cytoplasm to periplasm by the addition of a pelB leader sequ ence to the cloned protein. When expressed in yeast Pichia pastoris, Ag 5 w as secreted because the cloned protein contained a yeast alpha signal leade r sequence. Recombinant Ag 5 from yeast was shown to have the native struct ure of the natural protein and the recombinant Ag 5 from bacteria did not. This was shown by comparison of their solubility, electrophoretic behavior, disulfide bond content, CD spectrum, and binding of IgE antibodies from al lergic patients and IgG antibodies from mice immunized with natural Ag 5 or recombinant Ag 5s from yeast or bacteria. These studies were made with Ag 5s from yellowjacket (Vespula vulgaris) and paper wasp (Polistes annularis) . (C) 1999 Academic Press.