HETEROLOGOUS EXPRESSION OF FUNCTIONALLY ACTIVE HUMAN CYTOCHROMES P450 .2. MODELING OF XENOBIOTIC METABOLISM BY SACCHAROMYCES-CEREVISIAE CELLS EXPRESSING CYTOCHROME P450IIIA4

A cDNA encoding human cytochrome P450IIIA4 was modified by the PCR method for maximum expression in the Saccharomyces cerevisiae cells and recloned into a yeast expressing vector containing a galactose promoter. Expression of functionally active cytochrome P450IIIA4 was achieved in yeast cells. The protein showed a normal reduced CO spectrum in microsomes isolated from the induced yeast bearing the cytochrome P450IIIA4 gene. The microsomes catalyzed oxidative bioconversion of nifedipine, a specific substrate for cytochrome P450IIIA4.