6533b833fe1ef96bd129b791
RESEARCH PRODUCT
Genetically engineered V79 chinese hamster cell expression of purified cytochromeP-450iib1 monooxygenase activity
Karl-ludwig PlattS. DograJ. DöhmerElvira MolitorFranz Oeschsubject
MaleOxygenaseCytochromeCellTransfectionToxicologyIsozymeChinese hamsterCricetulusCytochrome P-450 Enzyme SystemCricetinaemedicineAnimalsTestosteroneCells CulturedChromatography High Pressure Liquidchemistry.chemical_classificationbiologyRats Inbred StrainsTransfectionKetosteroidsbiology.organism_classificationMolecular biologyRatsIsoenzymesmedicine.anatomical_structureEnzymeBiochemistrychemistryPhenobarbitalMicrosomes LiverOxygenasesbiology.proteinCricetulusGenetic EngineeringOxidation-Reductiondescription
Chinese hamster V79 fibroblasts, frequently used as target cells in short-term tests for mutagenicity, do not possess measurable monooxygenase activity; in particular, enzymatic oxidation of testosterone (T) cannot be demonstrated. If these V79 cells, however, had been transfected with the cDNA-encoding rat liver cytochrome P-450IIB1 under control of the SV40 early promoter, they stably expressed monooxygenase activity. These so-called SD1 cells then oxidatively metabolized T at a rate of 27 pmol/mg protein/min, converting it to 16 alpha- and 16 beta-hydroxy-T as well as 4-androsten-3,17-dione as sole metabolites in a ratio of 1.1:1.0:1.6. The regio- and stereoselective conversion of T by SD1 cells, as well as the quantitative distribution of the metabolites, corresponds well with the results reported for pure cytochrome P-450IIB1 in a reconstituted system.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1989-01-01 | Journal of Biochemical Toxicology |