Abstract
Effects of detergents such as cholate, deoxycholate and Triton X-100 were studied on N-and ring-hydroxylation of 2-acetamidofluorene by reconstituted and unresolved microsomal systems from livers of hamsters pretreated with 3-methylcholanthrene. Triton X-100 (2.5 mg/nmol of cytochrome P-448) inhibited N-and ring-hydroxylation by wholemicrosomal preparations by 40 and 90% respectively Deoxycholate at the same concentration inhibited both hydroxylations completely, whereas cholate inhibited N-and ring-hydroxylation by 40 and 50% respectively. In reconstitution studies, the presence of Triton X-100(0.5-1.0mg/nmol of cytochrome P-448) along with unsolubilized cytochrome P-448 fraction and solubilized reductase fraction increased N-hydroxylation to an appreciable extent compared with ring-hydroxylation. Both cholate and deoxycholate at 0.5-1.0 mg concentrations had a greater stimulatory effect on ring-than on N-hydroxylation activity in such a reconstituted system.
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Selected References
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- Alvares A. P., Schilling G., Levin W., Kuntzman R. Studies on the induction of CO-binding pigments in liver microsomes by phenobarbital and 3-methylcholanthrene. Biochem Biophys Res Commun. 1967 Nov 30;29(4):521–526. doi: 10.1016/0006-291x(67)90515-3. [DOI] [PubMed] [Google Scholar]
- Comai K., Gaylor J. L. Existence and separation of three forms of cytochrome P-450 from rat liver microsomes. J Biol Chem. 1973 Jul 25;248(14):4947–4955. [PubMed] [Google Scholar]
- Ichikawa Y., Yamano T. Reconversion of detergent- and sulfhydryl reagent-produced P-420 to P-450 by polyols and glutathione. Biochim Biophys Acta. 1967 May 9;131(3):490–497. doi: 10.1016/0005-2728(67)90008-4. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Lotlikar P. D., Baldy W. J., Jr, Dwyer E. N. Dimethylnitrosamine demethylation by reconstituted liver microsomal cytochrome P-450 enzyme system. Biochem J. 1975 Dec;152(3):705–708. doi: 10.1042/bj1520705. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lotlikar P. D., Enomoto M., Miller J. A., Miller E. C. Species variations in the N- and ring-hydroxylation of 2-acetylaminofluorene and effects of 3-methylcholanthrene pretreatment. Proc Soc Exp Biol Med. 1967 Jun;125(2):341–346. doi: 10.3181/00379727-125-32086. [DOI] [PubMed] [Google Scholar]
- Lotlikar P. D., Luha L., Zaleski K. Reconstituted hamster liver microsomal enzyme system for N-hydroxylation of the carcinogen 2-acetylaminofluorene. Biochem Biophys Res Commun. 1974 Aug 19;59(4):1349–1355. doi: 10.1016/0006-291x(74)90462-8. [DOI] [PubMed] [Google Scholar]
- Lotlikar P. D., Zaleski K. Inhibitory effect of carbon monoxide on the N- and ring-hydroxylation of 2-acetamidofluorene by hamster hepatic microsomal preparations. Biochem J. 1974 Nov;144(2):427–430. doi: 10.1042/bj1440427. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lotlikar P. D., Zaleski K. Ring-andN-hydroxylation of 2-acetamidofluorene by rat liver reconstituted cytochrome P-450 enzyme system. Biochem J. 1975 Sep;150(3):561–564. doi: 10.1042/bj1500561. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lu A. Y., Junk K. W., Coon M. J. Resolution of the cytochrome P-450-containing omega-hydroxylation system of liver microsomes into three components. J Biol Chem. 1969 Jul 10;244(13):3714–3721. [PubMed] [Google Scholar]
- Lu A. Y., Levin W. The resolution and reconstitution of the liver microsomal hydroxylation system. Biochim Biophys Acta. 1974 Sep 16;344(2):205–240. doi: 10.1016/0304-4157(74)90004-5. [DOI] [PubMed] [Google Scholar]
- Lu A. Y., Levin W., West S., Jacobson M., Ryan D., Kuntzman R., Conney A. H. The role of cytochrome P-450 and P-448 in drug and steroid hydroxylations. Ann N Y Acad Sci. 1973;212:156–174. doi: 10.1111/j.1749-6632.1973.tb47594.x. [DOI] [PubMed] [Google Scholar]
- Lu A. Y., West S. B. Reconstituted liver microsomal enzyme system that hydroxylates drugs, other foreign compounds, and endogenous substrates. 3. Properties of the reconstituted 3,4-benzypyrene hydroxylase system. Mol Pharmacol. 1972 Sep;8(5):490–500. [PubMed] [Google Scholar]
- Masters B. S., Baron J., Taylor W. E., Isaacson E. L., LoSpalluto J. Immunochemical studies on electron transport chains involving cytochrome P-450. I. Effects of antibodies to pig liver microsomal reduced triphosphopyridine nucleotide-cytochrome c reductase and the non-heme iron protein from bovine adrenocortical mitochondria. J Biol Chem. 1971 Jul 10;246(13):4143–4150. [PubMed] [Google Scholar]
- Miller J. A. Carcinogenesis by chemicals: an overview--G. H. A. Clowes memorial lecture. Cancer Res. 1970 Mar;30(3):559–576. [PubMed] [Google Scholar]
- Mitani F., Alvares A. P., Sassa S., Kappas A. Preparation and properties of a solubilized form of cytochrome P-450 from chick embryo liver microsomes. Mol Pharmacol. 1971 May;7(3):280–292. [PubMed] [Google Scholar]
- OMURA T., SATO R. THE CARBON MONOXIDE-BINDING PIGMENT OF LIVER MICROSOMES. I. EVIDENCE FOR ITS HEMOPROTEIN NATURE. J Biol Chem. 1964 Jul;239:2370–2378. [PubMed] [Google Scholar]
- Strobel H. W., Lu A. Y., Heidema J., Coon M. J. Phosphatidylcholine requirement in the enzymatic reduction of hemoprotein P-450 and in fatty acid, hydrocarbon, and drug hydroxylation. J Biol Chem. 1970 Sep 25;245(18):4851–4854. [PubMed] [Google Scholar]
- Thorgeirsson S. S., Jollow D. J., Sasame H. A., Green I., Mitchell J. R. The role of cytochrome P-450 in N-hydroxylation of 2-acetylaminofluorene. Mol Pharmacol. 1973 May;9(3):398–404. [PubMed] [Google Scholar]
- Weisburger J. H., Weisburger E. K. Biochemical formation and pharmacological, toxicological, and pathological properties of hydroxylamines and hydroxamic acids. Pharmacol Rev. 1973 Mar;25(1):1–66. [PubMed] [Google Scholar]
