Sequence analysis of cDNA coding for a major house dust mite allergen, Der f I.
A cDNA clone coding for Der f I, a major allergen from the house dust mite Dermatophagoides farinae has been isolated and sequenced. It codes for a putative 18-residue signal peptide, an 80-residue proenzyme region, and a 223-residue mature protein with a derived molecular weight of 25,191. The deduced amino-acid sequence shows significant homology to other cysteine proteases in the proregion as well as in the mature protein. Sequence alignment of the mature Der f I protein with the homologous allergen Der p I from the related mite D. pteronyssinus revealed a high degree of homology (81%) between the two proteins, as predicted by previous sequencing at the protein level. In particular, the residues comprising the active site of these enzymes and the cysteine residues were conserved. A potential N-glycosylation site was present at an equivalent position in both mite allergens. It is anticipated that the availability of recombinant Der f I will facilitate epitope mapping studies and studies of T-cell function in mite allergy by providing high levels of pure allergen.
Dilworth
R J
RJ
Western Australian Research Institute for Child Health, Princess Margaret Hospital for Children, Subiaco.
Chua
K Y
KY
Thomas
W R
WR
D000485:Allergens / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000032:analysis*; D004391:Dust; D008925:Mites / Q000276:immunology*; D008969:Molecular Sequence Data
D000485:Allergens; D004391:Dust; D004247:DNA