cDNA cloning of the 43-kDa latex allergen Hev b 7 with sequence similarity to patatins and its expression in the yeast Pichia pastoris

Authors


  • Correspondence to H. Breiteneder, Department of General and Experimental Pathology, University Hospital, AKH-EBO-3Q, Waehringer Guertel 18−20, A-1090 Vienna, Austria

  • Fax: +43 1 40400 5130.

  • E-mail:Heimo.Breiteneder@akh-wien.ac.at

  • Abbreviations. RAST, radioallergosorbent test; NRL, natural rubber latex; PNGase F, peptide N-glycosidase F; pfu, plaque-forming units.

  • Enzyme. Peptide N-glycosidase F ( EC3.5.1.52).

  • Note. The nucleotide sequence reported in this paper has been submitted to the EMBL database and assigned the accession number AJ223038.

Abstract

IgE-mediated hypersensitivity to latex proteins present in health care products, particularly in latex gloves, has become an important public health problem in recent years. We purified natural Hev b 7, a 43-kDa patatin-like allergen from the latex of Hevea brasiliensis and determined several internal peptide sequences. A heterologous hybridization probe of a patatin gene of potato, to which these peptides could be aligned 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 kDa. The deduced amino acid sequence had 39−42 % identity to patatins from Solanum tuberosum. The purified recombinant Hev b 7 expressed in the yeast Pichia pastoris displayed, similarly to patatins from S. tuberosum, esterase activity. Both natural and recombinant Hev b 7 were recognized 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-terminal leader peptide for targeting to the endoplasmatic reticulum and was not glycosylated. These results establish the 43-kDa patatin-like protein as a latex allergen and raise the possibility of different cellular localization and function compared to S. tuberosum patatins.

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