DETERMINATION OF 3 DISULFIDE BONDS IN A MAJOR HOUSE-DUST MITE ALLERGEN, DER-F-II

Der f II is major mite allergen consisting of 129 amino acid residues. Der f II contains six cysteine residues, suggesting the existence of three disulfide bonds which would stabilize this small protein. As the first step in revealing the relationship between the structure and th e allergenic property of Der f II, the formation of disulfide bonds wa s examined. Der f II purified from Dermatophagoides farinae was treate d with lysylendopeptidase or proline-specific endopeptidase, and the p eptide fragments thus generated were separated by reverse phase high p erformance liquid chromatography. Determination of the amino acid sequ ence of each peptide collected in this way proved the existence of thr ee disulfide bonds between Cys8 and Cys119, Cys21 and Cys27, and Cys73 and Cys78.