Association of cytochrome b5 and cytochrome P-450 reductase with cytochrome P-450 in the membrane of reconstituted vesicles.
J Biol Chem 1982 May; 257(9):4783-4787
The interaction of cytochrome-P-450 and NADPH-cytochrome-P-450- reductase was studied in vesicle reconstituted systems. Cytochrome-P- 450 and NADPH-cytochrome-P-450-reductase were derived from livers of rabbits pretreated with phenobarbital. The cytochrome-P-450 and NADPH-cytochrome-p-450 were reconstituted into phospholipid vesicles. The vesicle systems contained sufficient phospholipid that no protein/protein interaction would be induced solely to prevent exposure of hydrophobic protein surfaces to the aqueous environment. Cytochrome-b5 was included in order to study a more complete NADPH dependent electron chain. The bilayer of these vesicles was composed of a 2:1 mixture of phosphatidylcholine and phosphatidylethanolamine which provided functional and structural similarity to microsomes. Complex formation in the membrane was studied by magnetic CD. Enzymatic measurements were used to study the stimulatory role of cytochrome-b5 and to obtain information on the electrostatic nature of the protein/protein interactions. The data supported a model of specific reversible association reactions in a two dimensional phospholipid bilayer in which electrostatic interactions are involved. The authors conclude that there is a requirement for at least one charge pairing for electron transfer from reductase to cytochrome-P-450.
NIOSH-Publication; NIOSH-Grant; Grants-other; Enzyme-activity; Liver-enzymes; Protein-chemistry; In-vitro-studies
Anesthesia Stanford University Department of Anesthesia Stanford, Calif 94305
Other Occupational Concerns; Grants-other
Journal of Biological Chemistry
Stanford University, Stanford, California