Cloning of the patatin-like latex allergen Hev b 7, its expression in the yeast Pichia pastoris and its immunological characterization

The 43-kD latex allergen Hev b 7 was purified from the latex of Hevea brasiliensis and identified by N-terminal and internal peptide sequences as highly homologous to patatins. Patatins are storage proteins encoded by a multigene family found in plants such as potato and tomato, We have obtained a cDNA clone coding for a cytoplasmic form of Hev b 7, The recombinant protein was expressed in the methylotrophic yeast Pichia pastoris at 10 mg/l culture supernatant. Both natural Hev b 7 and rHev b 7 were recognized by IgE in 11% of the latex-allergic patients, rHev b 7 inhibited binding to its counterpart in natural rubber latex extracts, Purified rHev b 7 used at concentrations of in mu g/ml in skin prick tests produced wheal-and-flare reactions of sizes equal to those produced by nHev b 7, Furthermore, we were able to show that rHev b 7 possessed esterase activity. A plant expression system for the production of larger quantities of recombinant latex allergens as an alternative to the preparation from H. brasiliensis sap is discussed.