CLONING AND CHARACTERIZATION OF A GROUP-II ALLERGEN FROM THE DUST-MITE TYROPHAGUS-PUTRESCENTIAE

The complete cDNA encoding a major allergen from the dust mite Tyropha gus putrescentiae, Tyr p 2, has been sequenced and expressed. A degene rate primer was designed to the N-terminal amino acid sequence of the 16-kDa protein. The complete cDNA sequence was achieved by using rever se transcriptase PCR, PCR+1, standard cloning and sequencing technique s. The cDNA of Tyr p 2 is 552 nucleotides in length from the start cod on including 126 nucleotides after the stop codon up to the beginning of the poly(A) tail. The leader sequence consists of 15 amino acids. R egarding the predicted amino acid sequence, there are no potential N g lycosylation sites (N-X-S/T). The sequence showed similarity to group II allergens from other mite species, and some regions are completely conserved. To show that the cloned cDNA sequence was coding for an all ergen, Tyr p 2 was expressed in Escherichia coli and shown to react wi th a T. putrescentiae-positive serum pool.