Cytochrome P-450 C-M/F, new constitutive form of microsomal cytochrome P-450 in male and female rat liver with estrogen 2- and 16.alpha.-hydroxylase activity
- 26 January 1988
- journal article
- research article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 27 (2), 678-686
- https://doi.org/10.1021/bi00402a028
Abstract
A new cytochrome P-450 isozyme, P-450C-M/F, has been purified from untreated rat liver microsomes. The purified preparation was electrophoretically homogeneous and contained 12-15 nmol of P450/mg of protein and had a minimum molecular weight of 48,500. the NH2-terminal amino acid sequence of P-450C-m/F was different from that of other P-450''s. Immunoblot analysis of microsomes demonstrated that P-450C-M/F was present in the liver of untreated male as well as female rats. Treatment of rats with phenobarbital, 3-methylcholanthrene, or .beta.-naphthoflavone did not induce P-450C-M/F. Cytochrome P-450C-M/F exhibited little activities of 7-ethoxycoumarin and 7-ethoxyresorufin O-deethylation or hydroxylation of arylhydrocarbon, testosterone, androstenedione, and progesterone. In contrast, it was highly active in N-demethylation of ethylmorphine and benzphetamine and in 2- and 16.alpha.-hydroxylation of estrogens, particularly that of estradiol. These studies establish that cytochrome P-450C-M/F is constitutively present in both male and female rats and suggest that it may be involved in the oxidative metabolism of estradiol, particularly in the formation of estriol, the uterotropic metabolite of estradiol.This publication has 46 references indexed in Scilit:
- Estrogen 2-hydroxylase: Activity in rat tissuesSteroids, 1978
- COMPARATIVE STUDIES ON THE METABOLISM OF OESTRADIOL IN THE BRAIN, THE PITUITARY AND THE LIVER OF THE RATActa Endocrinologica, 1978
- Some properties of a detergent-solubilized NADPH-cytochrome c(cytochrome P-450) reductase purified by biospecific affinity chromatography.Journal of Biological Chemistry, 1976
- PHARMACOLOGICAL IMPLICATIONS OF MICROSOMAL ENZYME INDUCTION1967
- Photochemical Action Spectrum of the Terminal Oxidase of Mixed Function Oxidase SystemsScience, 1965
- SIMILARITIES BETWEEN OXIDATIVE DRUG-METABOLIZING ENZYMES + STEROID HYDROXYLASES IN LIVER MICROSOMES1964
- CARBON MONOXIDE-BINDING PIGMENT OF LIVER MICROSOMES .I. EVIDENCE FOR ITS HEMOPROTEIN NATURE1964
- UNTERSUCHUNGEN UBER DEN ZEITLICHEN VERLAUF DER 6-HYDROXYLIERUNG UND 16-ALPHA-HYDROXYLIERUNG VON OSTROGENEN DURCH RATTENLEBERSCHNITTE1960
- The colorimetric estimation of formaldehyde by means of the Hantzsch reactionBiochemical Journal, 1953
- PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENTJournal of Biological Chemistry, 1951