Micromolar quantities of hematin, when added to reaction flasks containing homogenates of extra-hepatic tissues, benzo(a)pyrene, and cofactors necessary for monooxygenation, caused up to a 40-fold enhancement of aryl hydrocarbon (benzo(a)pyrene) hydroxylase (EC 184.108.40.206) activity. Pretreatment of rats with 3-methylcholanthrene caused a reduction in the stimulatory effect of hematin. Metabolic profiles of 7,12-dimethylbenz(a)anthracene, obtained with high pressure liquid chromatography, illustrated the enhancement of monooxygenase activity by hematin at methyl carbons. It is speculated that the mechanism of the hematin effect is the reconstitution of a small pool, or pools, of apo-(cytochrome P-450) which exist in these extra-hepatic tissues, resulting in the formation of functional holoenzyme.
|Original language||English (US)|
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Aug 14 1978|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology