DIRECT EXPRESSION OF DER F2, A MAJOR HOUSE-DUST MITE ALLERGEN, IN ESCHERICHIA-COLI

Der f2 protein in a highly antigenic form was directly expressed in ba cteria. Plasmid pFLU11 derived from pKK233-2 was designed to express m ethionyl-Der f2 under the control of the trc promoter and it has the r eplication origin of pUC118 instead of its original to increase the co py number. This expression plasmid directed the synthesis of recombina nt Der f2 (rDer f2) protein in an insoluble form of inclusion bodies i n Escherichia coli cells. The high copy number plasmid pFLU11 conferre d the efficient production of the Der f2 protein in E. coli, when comp ared to a nonchanged origin material, rDer f2 inclusion bodies were ea sily solubilized in urea and renatured by dialysis to assume the activ e form. The rDer f2 protein was purified by means of anion exchange an d gel filtration chromatography. This expression system yielded about 10 mg of purified rDer f2 protein from the IL culture. Purified rDer f 2 protein reacted with IgE from patient sera almost identically to the native Der f2 in the RAST enzyme immunoassay and skin prick test.