Cloning and expression of cDNA encoding the complete prepro-form of an isoform of Der f 1, the major group 1 allergen from house dust mite Dermatophagoides farinae

cDNA clones encoding a major house dust mite allergen, Der f 1, were isolated from a Dermatophagoides farinae cDNA library by plaque immunoscreening using rabbit anti-Der fl serum. The sequences cover the complete open reading frame encoding the prepro-form, The sequence Is different from previously reported cDNA of Der fl in six bases and the encoded amino acid sequence is different in two residues, Pro-forms of Der fl and its mutant, in which the N-glycosylation motif was disrupted, expressed in Pichia pastoris were converted to the mature forms by an in vitro activation process and they showed significant IgE-binding, The biologically active rDer f 1 molecules would be useful for diagnostic testing and allergen-specific immunotherapy, In contrast, Der f 1 directly expressed in Escherichia coli without the prosequence had very low IgE binding, The hypoallergenic Der f 1 polypeptide could be useful for safer and more effective immunotherapy.