CLONING AND EXPRESSION IN ESCHERICHIA-COLI OF CDNA-ENCODING HOUSE-DUST MITE ALLERGEN DER-F-3, SERINE-PROTEASE FROM DERMATOPHAGOIDES-FARINAE

Der f 3 is one of the allergens produced by house dust mite Dermatopha goides farinae showing serine protease activity, Based on its amino ac id sequence, a cDNA clone encoding Der f 3 was isolated from a cDNA li brary of D. farinae, Sequencing analysis of the clone revealed the pre sence of an open reading frame of 780 bp, which encodes a mature prote in of 232 amino acids with 27 amino acids of pre-pro sequence at the N -terminus. When proDer f 3 was produced in Escherichia coli as a fused protein with glutathione-S-transferase, the fused protein was accumul ated as inclusion bodies, The protein purified with 8 M urea and gluta thione-affinity column chromatography, however, did not show protease activity, When an arginine residue,vas introduced at the C-terminus of the pro-region in place of threonine, removal of the pro-region to pr oduce an active mature protease was observed, The specificity and the activity of this recombinant protease were almost the same as those of native Der f 3.