CDNA CLONING OF THE 43-KDA LATEX ALLERGEN HEV-B-7 WITH SEQUENCE SIMILARITY TO PATATINS AND ITS EXPRESSION IN THE YEAST PICHIA-PASTORIS

IgE-mediated hypersensitivity to latex proteins present in health care products, particularly in latex gloves, has become an important publi c health problem in recent years. We purified natural Kev b 7, a 43-kD a patatin-like allergen from the latex of Hevea brasiliensis and deter mined several internal peptide sequences. A heterologous hybridization probe of a patatin gene of potato, to which these peptides could be a ligned best, was used to screen a latex cDNA library. The cDNA encoded an acidic protein of 388 amino acids with a molecular mass of 42.9 kD a. The deduced amino acid sequence had 39-42 % identity to patatins fr om Solanum tuberosum. The purified recombinant Hev b 7 expressed in th e yeast Pichia pastoris displayed, similarly to patatins from S. tuber osum, esterase activity. Both natural and recombinant Hev b 7 were rec ognized by IgE from sera of latex-sensitized allergic individuals. In contrast to patatins from S. tuberosum and Nicotiana tabacum, natural Hev b 7 lacked an N-terninal leader peptide for targeting to the endop lasmatic reticulum and was not glycosylated. These results establish t he 43-kDa patatin-like protein as a latex allergen and raise the possi bility of different cellular localization and function compared to S. tuberosum patatins.