Amino acid sequence of Fel dI, the major allergen of the domestic cat: protein sequence analysis and cDNA cloning.

The complete primary structure of Fel dI (International Union of Immunological Societies nomenclature), the major allergen produced by the domestic cat, Felis domesticus, was determined by protein sequence analysis and cDNA cloning. Protein sequencing of Fel dI from an immunoaffinity-purified extract of house dust revealed that the allergen is composed of two polypeptide chains. Degenerate oligonucleotides derived from the protein sequence were used in polymerase chain reaction amplification of cat salivary gland cDNA to demonstrate that the two chains are encoded by different genes. Chain 1 of Fel dI shares amino acid homology with rabbit uteroglobin, while chain 2 is a glycoprotein with N-linked oligosaccharides.