M. Franklin, R. Estabrook
Mar 1, 1971
Citations
2
Influential Citations
173
Citations
Quality indicators
Journal
Archives of biochemistry and biophysics
Abstract
Abstract The organic mercurial, mersalyl, causes a 50% inhibition of TPNH-cytochrome c reductase activity, TPNH-cytochrome P-450 reductase activity, and ethylmorphine N -demethylation in rat liver microsomes at concentrations of about 25 mμmoles/mg microsomal protein. The K i (mersalyl) proved to be independent of whether the overall hydroxylation activity was enhanced by the addition of DPNH, or an increased ionic strength; or was inhibited by carbon monoxide. Mersalyl, at a concentration of 25 mμmoles/mg protein, caused no extensive conversion of cytochrome P-450 to P-420. Studies on the pattern of inhibition suggest a rigid electron-transport system linking a single molecule of TPNH-cytochrome c reductase to a number of molecules of cytochrome P-450 contained within a multicomponent complex and that reducing equivalents can be transferred only within a single enzyme complex with no demonstrable electron transfer interactions between the components of different complexes.