J. Biochem, 1986, Vol. 99, No. 3 741-749
© 1986 Japanese Biochemical Society
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Monooxygenase Activity of Saccharomyces cerevisiae Cells Transformed with Expression Plasmids Carrying Rat Cytochrome P-450MC cDNA1
Takarazuka Research Center, Sumitomo Chemical Co., Ltd. Takatsukasa, Takarazuka, Hyogo 665
The recombinant plasmids pAMC1 and pJMCl were constructed; the former contained the cytochrome P-450MC (P-450MC) cDNA expression unit consisting of yeast alcohol dehydrogenase I (ADH) promoter, rat P-450MC cDNA and ADH terminator, and the Leu 2 marker gene, and the latter contained the same expression unit and the leu 2-d gene. Saccharomyces cerevisiae AH22 cells transformed with each of the recombinant plasmids were examined for plasmid copy number, P-450MC mRNA level, P-450MC content, and monooxygenase activity. The S. cerevisiae AH22/pJMC1 cells contained about 2-fold higher levels of the plasmid, P-450MC mRNA, and P-450MC than the AH22/pAMC1 cells. Monooxygenase activity towards 7-ethoxycoumarin and acetanilide of the AH22/pJMC1 cells was 1.7-fold and 1.5-fold higher than that of the AH22/pAMC1 cells, respectively, whereas the activity of the AH22/pAMC1 cells towards 7-ethoxycoumarin and acetanilide was more than 1,000-fold and 10-fold higher than that of the control AH22/pAAH5 cells which contain no P-450MC cDNA, respectively. Therefore, it is likely that monooxygenase activity of the AH22 cells carrying rat P-450MC cDNA was approximately proportional to the expression level of P-450MC cDNA.
1 This study was supported by funds obtained under the Research and Development Project of Basic Technologies for Future Industries from the Ministry of International Trade and Industry of Japan.