Metabolic Activation of Adriamycin by Nadph-Cytochrome P-450 Reductase, Rat Liver and Heart Microsomes and Covalent Protein Binding of Metabolites

1982 ◽  
pp. 471-485 ◽  
Author(s):  
Max E. Scheulen ◽  
Hermann Kappus
Keyword(s):  
Protein Binding ◽  
Rat Liver ◽  
Metabolic Activation ◽  
Nadph Cytochrome ◽  
Covalent Protein Binding ◽  
Cytochrome P 450

scholarly journals Metabolic Activation and Covalent Protein Binding of Berberrubine: Insight into the Underlying Mechanism Related to Its Hepatotoxicity

2020 ◽  
Vol Volume 14 ◽  
pp. 4423-4438
Author(s):  
Kai Wang ◽  
Jinqiu Rao ◽  
Tingting Zhang ◽  
Qing Gao ◽  
Jichao Zhang ◽  
...  
Keyword(s):  
Protein Binding ◽  
Metabolic Activation ◽  
Underlying Mechanism ◽  
Covalent Protein Binding ◽  
Insight Into

scholarly journals Immunochemical characterization of NADPH-cytochrome P-450 reductase from Jerusalem artichoke and other higher plants

1989 ◽  
Vol 259 (3) ◽  
pp. 847-853 ◽  
Author(s):  
I Benveniste ◽  
A Lesot ◽  
M P Hasenfratz ◽  
F Durst
Keyword(s):  
Cytochrome C ◽  
Rat Liver ◽  
Higher Plants ◽  
Polyclonal Antibodies ◽  
Reductase Activity ◽  
Jerusalem Artichoke ◽  
Cross Reactivity ◽  
Cytochrome C Reductase ◽  
Nadph Cytochrome ◽  
Cytochrome P 450

Polyclonal antibodies were prepared against NADPH-cytochrome P-450 reductase purified from Jerusalem artichoke. These antibodies inhibited efficiently the NADPH-cytochrome c reductase activity of the purified enzyme, as well as of Jerusalem artichoke microsomes. Likewise, microsomal NADPH-dependent cytochrome P-450 mono-oxygenases (cinnamate and laurate hydroxylases) were efficiently inhibited. The antibodies were only slightly inhibitory toward microsomal NADH-cytochrome c reductase activity, but lowered NADH-dependent cytochrome P-450 mono-oxygenase activities. The Jerusalem artichoke NADPH-cytochrome P-450 reductase is characterized by its high Mr (82,000) as compared with the enzyme from animals (76,000-78,000). Western blot analysis revealed cross-reactivity of the Jerusalem artichoke reductase antibodies with microsomes from plants belonging to different families (monocotyledons and dicotyledons). All of the proteins recognized by the antibodies had an Mr of approx. 82,000. No cross-reaction was observed with microsomes from rat liver or Locusta migratoria midgut. The cross-reactivity generally paralleled well the inhibition of reductase activity: the enzyme from most higher plants tested was inhibited by the antibodies; whereas Gingko biloba, Euglena gracilis, yeast, rat liver and insect midgut activities were insensitive to the antibodies. These results point to structural differences, particularly at the active site, between the reductases from higher plants and the enzymes from phylogenetically distant plants and from animals.

scholarly journals Presence of nadph-cytochrome P-450 reductase in rat liver golgi membranes: Evidence obtained by immunoadsorption method

1978 ◽  
Vol 79 (2) ◽  
pp. 590-597 ◽  
Author(s):  
A Ito ◽  
GE Palade
Keyword(s):  
Rat Liver ◽  
Reductase Activity ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Nadph Cytochrome ◽  
Golgi Membranes ◽  
Cyt C ◽  
Bona Fide ◽  
Liver Homogenates ◽  
Cytochrome P 450

Light Golgi fractions (GF(1+2)) prepared from rat liver homogenates by a modification of the Ehrenreich et al. procedure (J. Cell Biol. 59:45) had significant NADPH-cytochrome P(450) reductase (NADPH-cyt c reductase) activity if assayed immediately after their isolation. An antibody raised in rabbits against purified microsomal and Golgi fractions. To find out whether this activity is located in bona fide Golgi elements or in contaminating microsomal vesicles, we used the following 3-step immunoadsorption procedure: (a) antirabbit IgG (raised in goats) was conjugated to small (2-5 μm) polycrylamide (PA) beads; (b) rabbit anti NADPH-cyt c reductase was immunoadsorbed to the antibody-coated beads; and (c) GF(1+2) was reacted with the beads carrying the two successive layers of antibodies. The beads were then recovered by centrifugation, and were washed, fixed, embedded in agarose, and processed for transmission electromicroscopy. Antireductase- coated beads absorbed 60 percent of the NADPH-cyt c reductase (and comparable fractions of NADH-cyt c reductase and glucose-6-phosphatase) but only 20 percent of the galactosyltransferase activity of the input GF(1+2). Differential vesicle counts showed that approximately 72 percent of the immunoadsorbed vesicles were morphologically recognizable Golgi elements (vesicles with very low density lipoprotein [VLDL] clusters or Golgi cisternae); vesicles with single VLDL and smooth surfaced microsome-like vesicles were too few (approximately 25 percent) to account for the activity. It is concluded that NADPH-cytochrome P(450) reductase is a Golgi membrane enzyme of probably uneven distribution among the elements of the Golgi complex.

The role of metabolic activation by cytochrome P-450 in covalent binding of VP 16-213 to rat liver and HeLa cell microsomal proteins

1985 ◽  
Vol 21 (9) ◽  
pp. 1099-1106 ◽  
Author(s):  
J.M.S. van Maanen ◽  
C. de Ruiter ◽  
J. de Vries ◽  
P.R. Kootstra ◽  
F. Gobas ◽  
...  
Keyword(s):  
Hela Cell ◽  
Rat Liver ◽  
Covalent Binding ◽  
Metabolic Activation ◽  
Cytochrome P 450

One-electron reduction of mitomycin c by rat liver: Role of cytochrome P-450 and NADPH-cytochrome P-450 reductase

Xenobiotica ◽  
1990 ◽  
Vol 20 (9) ◽  
pp. 967-978 ◽  
Author(s):  
R. M. Vromans ◽  
R. van de Straat ◽  
M. Groeneveld ◽  
N. P. E. Vermeulen
Keyword(s):  
Mitomycin C ◽  
Rat Liver ◽  
Nadph Cytochrome ◽  
Electron Reduction ◽  
Cytochrome P 450

scholarly journals Characterization of a phenobarbital-inducible cytochrome P-450, NADPH-cytochrome P-450 reductase and reconstituted cytochrome P-450 mono-oxygenase system from rat brain. Evidence for constitutive presence in rat and human brain

1992 ◽  
Vol 288 (2) ◽  
pp. 483-488 ◽  
Author(s):  
H K Anandatheerthavarada ◽  
M R Boyd ◽  
V Ravindranath
Keyword(s):  
Human Brain ◽  
Rat Brain ◽  
Rat Liver ◽  
Specific Content ◽  
Nadph Cytochrome ◽  
Apparent Homogeneity ◽  
Brain Microsomes ◽  
Molecular Masses ◽  
Reconstituted System ◽  
Cytochrome P 450

Cytochrome P-450 was purified to apparent homogeneity from the brain microsomes of phenobarbital-treated rats. The specific content of the purified P-450 was 12.7 nmol/mg of protein. NADPH-cytochrome P-450 reductase (reductase) was also purified to apparent homogeneity from brain microsomes. The specific content was 34.7 mumol of cytochrome c reduced/min per mg of protein. The reduced carbon monoxide spectrum of purified P-450 exhibited a peak at 450 nm. Both the P-450 and the reductase moved as single bands on SDS/PAGE. The molecular masses of the purified P-450 and the reductase were determined to be 53.3 and 72.0 kDa respectively. The purified brain P-450 cross-reacted with antibodies to rat liver P-450IIB1/IIB2 when examined by Western immunoblotting, but no immunological similarity was observed with rat liver P-450IA1/IA2 or P-450IIE1. Purified rat brain reductase cross-reacted with antibodies to rat liver reductase. Further, immunoblot experiments with untreated rat and human brain microsomes using antisera to the purified rat brain P-450 and reductase indicated that these forms of P-450 and NADPH-cytochrome P-450 reductase exist constitutively in rat and human brain. Purified rat brain P-450 was reconstituted with purified NADPH-cytochrome P-450 reductase, deoxycholate and dilauroyl glyceryl 3-phosphocholine. NADPH-dependent N-demethylation of aminopyrine and morphine was observed in the reconstituted system. The catalytic-centre activities were 80.25 and 38.2 nmol of formaldehyde formed/min per nmol of P-450 respectively. The reconstituted system had a comparatively lower catalytic-centre activity for 7-ethoxycoumarin O-de-ethylase (10.5 nmol of product formed/min per nmol of P-450).

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