Structural gene products of the Ah locus. Genetic and immunochemical evidence for two forms of mouse liver cytochrome P-450 induced by 3-methylcholanthrene.

نویسندگان

  • M Negishi
  • D W Nebert
چکیده

With the use of heterogenic stock (HS) mice, more than g-fold differences in hepatic microsomal 3-methylcholanthrene-inducible aryl hydrocarbon (benzo[alpyrene) hydroxylase (EC 1.14.14.2) activity and at least 4-fold differences in 3-methylcholanthrene-inducible acetanilide 4-hydroxylase activity were found. These data strongly suggest independent genetic control of two inducible cytochrome P-450-mediated monooxygenase activities known to be associated with the murine Ah locus. The procedure is described for isolating two inducible forms of partially separated P-450 from C57BL/6N treated with 3-methylcholanthrene, and an antibody to each of these forms was developed. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a molecular weight of about 55,000 is estimated for both partially separated hemoproteins. Limited proteolysis reveals differences in the peptide composition of these two cytochromes. PI-450 is more closely associated with polycyclic aromatic compound-inducible aryl hydrocarbon hydroxylase activity and NADPH oxidation in the presence of benzo[a]pyrene, whereas P-448 is more closely associated with polycyclic aromatic compoundinducible acetanilide 4-hydroxylase activity and NADPH oxidation in the presence of acetanilide. The Soret peaks of the reduced hemoprotein*CO complex are about 449.3 and 448.0 nm for PI-450 and P-448, respectively. Goat anti-PI-450 immunoglobulin inhibits 3-methylcholanthrene-inducible aryl hydrocarbon hydroxylase activity while not affecting 3-methylcholanthrene-inducible acetanilide 4-hydroxylase activity. Rabbit anti-P-448 immunoglobulin blocks 3-methylcholanthrene-inducible acetanilide 4-hydroxylase activity while not affecting 3-methylcholanthrene-inducible aryl hydrocarbon hydroxylase activity. Evidence is also presented for the possible presence of P-448 in the liver microsomes of the control, untreated mouse. By means of the pyridoxal phosphate/NaB[:‘H& method for labeling intact microsomes in vitro followed by immunoprecipitation, it was confirmed that transplacental PI-450 induction (and its associated aryl hydrocarbon hydroxylase activity) in fetal mouse liver by 2,3,7,8-tetrachlorodibenzo-p-dioxin develops earlier in gestational age than P-448 induction (and its associated acetanilide 4-hydroxylase activity) by 2,3,7,8-tetrachlorodibenzo-p-dioxin. These data, plus studies involving inhibitors in vitro,

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Genetic aspects of toxicity during development.

The Ah locus in the mouse controls the induction of cytochrome P1-450 and at least eleven associated monooxygenase activities. These enzyme systems metabolically potentiate and detoxify drugs, environmental pollutants, and other foreign chemicals, as well as numerous endogenous substrates. For certain substrates, it is known that cytochrome P1-450 produces different reactive intermediates and p...

متن کامل

Evidence for Transcriptional Control of Cytochrome Pi-450 Induction by Use of a Cloned Dna Sequence*

Clone 46 was recently shown by both immunologic and genetic criteria (Negishi, M., Swan, D. C., Enquist, L. W., and Nebert, D. W. (1981) h c . Natl. Acad Sci. U. S. A. 78, 800-804) to represent a cloned DNA sequence encoding 3-methylcholanthrene-induced cytochrome P1-450, a structural gene product of the [Ah] complex. Liver DNA from control, 3-methylcholanthrene-treated and 2,3,7,8-tetrachlorod...

متن کامل

Pyrolysis products from amino acids and protein: highest mutagenicity requires cytochrome P1-450.

Pyrolysis products of proteins and amino acids are highly mutagenic, but metabolism of these chemicals by rat liver subcellular fractions is known to be required for production of the mutagenic intermediates. We examined the mutagenesis of seven purified pyrolysis products from tryptophan, lysine, glutamic acid, and soybean globulin with Salmonella typhimurium strain TA98 in the presence of liv...

متن کامل

Immunochemical detection of different isoenzymes of cytochrome P-450 induced in chick hepatocyte cultures.

This study investigated whether the same cytochrome P-450 (P-450) isoenzymes were inducible in cultures of chick-embryo hepatocytes as in the liver of chicken embryos. We purified two isoenzymes of cytochrome P-450 from the livers of 17-day-old-chick embryos: one of molecular mass approx. 50 kDa induced in vivo by the phenobarbital-like inducer glutethimide, and the second of approx. 57 kDa ind...

متن کامل

Detection and purification of cytochromes P-450 in animal tissues with monoclonal antibodies.

Monoclonal antibody (MAb)-based radioimmunoassay (RIA) and immunopurification procedures were used to probe the immunochemical relatedness of cytochromes P-450 in tissues from different species. RIAs based on MAb 1-7-1 and MAb 1-31-2, both to the major 3-methylcholanthrene (MC)-induced rat liver microsomal cytochrome P-450, detected antigenically related forms of cytochrome P-450 in liver micro...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • The Journal of biological chemistry

دوره 254 21  شماره 

صفحات  -

تاریخ انتشار 1979