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2278652 
Journal Article 
Multiple forms of noninduced rat liver cytochrome P-450: Metabolism of 1-(4'-ethylphenoxy)-3,7-dimethyl-6,7-epoxy-trans-2-octene by reconstituted preparations 
Agosin, M; Morello, A; White, R; Repetto, Y; Pedemonte, J 
1979 
Yes 
Journal of Biological Chemistry
ISSN: 0021-9258
EISSN: 1083-351X 
HEEP/80/07422 
254 
19 
9915-9920 
WOS:A1979HQ50700089 
HEEP COPYRIGHT: BIOL ABS. A simple and reproducible procedure for the isolation of 2 forms of cytochrome P-450 from noninduced rat liver microsomes is reported. They are designated by their maximum absorbance in the CO difference spectrum as cytochrome P-450 and cytochrome P-451. Other spectral characteristics indicate that both species correspond to a low spin hemoprotein. P-450 has a subunit MW of 52,200, a 430 nm/455 nm ratio of 1.25 in the ethyl isocyanide difference spectrum, and a specific content of close to 12 nmol per mg of protein. P-451 has a subunit MW of 52,400, a 430 nm/455 nm ratio of 1.66 in the ethyl isocyanide difference spectrum, and a specific contenter mg of protein. Amino acid analysis indicates close similarities, but P-450 hase a high glycine content. Both P-450 and P-451 in a reconstituted system convert RO-20458 (1-(4'-ethylphenoxy)-3,7-dimethyl-6,7-epoxy-trans-2-octene), a juvenile hormone analog, to a polar metabolite but the rate of conversion is higher for P-451. The hemoproteins also differ in their rates of N-demethylation of benzphetamine and p-chloro-N-methylaniline and the O-de-ethylation of 7-ethoxyresorufin. Chromatographic and mass spectral evidence indicate that the RO-20458 polar metabolite corresponds to 1-(4'-(1-hydroxyethyl)-phenoxy)-3,7-dimethyl-6,7-epoxy-trans-2-octene.