Interactions of styrene and styrene oxide with partially purified cytochrome P-450 and P-448 from rat liver microsomes.
Styrene and styrene 7,8-oxide were able to bind both to partially purified cytochrome P-450 isolated from phenobarbital (PB)-treated rat liver and to cytochrome P-448 from liver microsomes of 3-methylcholanthrene (3-MC)-treated rats. In the presence of either purified preparation or "fresh" microsomes from PB- or 3-MC-treated animals, styrene produced a characteristic Type I difference spectrum as did styrene 7,8-oxide with "fresh" microsomes from PB rats. In other experiments, the addition of styrene oxide produced spectra which resembled Type I spectra but were somewhat shifted to longer wavelengths. A comparison of the binding parameters for the interaction of styrene or styrene 7,8-oxide with partially purified preparations and "fresh" microsomes indicated that the binding is catalyzed by more than one type of P-450 hemoprotein and that the binding affinity is slightly reduced by the purification procedure. The addition of phosphatidylcholine was unable to restore the binding parameters.
D000818:Animals; D019388:Cytochrome P-450 CYP1A2; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D003580:Cytochromes / Q000378:metabolism*; D004852:Epoxy Compounds / Q000378:metabolism*; D004988:Ethers, Cyclic / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D010713:Phosphatidylcholines / Q000378:metabolism; D011485:Protein Binding; D051381:Rats; D011919:Rats, Inbred Strains; D020058:Styrene; D013343:Styrenes / Q000378:metabolism*
D003580:Cytochromes; D004852:Epoxy Compounds; D004988:Ethers, Cyclic; D010713:Phosphatidylcholines; D013343:Styrenes; D020058:Styrene; D003577:Cytochrome P-450 Enzyme System; C013690:styrene oxide; C017170:Cyp1a2 protein, rat; D019388:Cytochrome P-450 CYP1A2