3-Hydroxy-3-methylglutaryl coenzyme A reductase activity in beef adrenal cortex

1978 ◽  
Vol 56 (10) ◽  
pp. 958-962 ◽  
Author(s):  
B. Preiss ◽  
L. Tan ◽  
J.-G. Lehoux
Keyword(s):  
Adrenal Cortex ◽  
Sucrose Gradient ◽  
Microsomal Fraction ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Zona Glomerulosa ◽  
Zona Fasciculata ◽  
Hmg Coa Reductase ◽  
Coa Reductase ◽  
Coenzyme A Reductase

3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) activity (mevalonate:NADP+ oxidoreductase (CoA-acylating) EC 1.1.1.34) was demonstrated in beef adrenal cortex. Most of the HMG-CoA reductase activity is in the microsomal fraction while a small percentage of the activity is associated with the mitochondria, Mitochondria purified on a linear sucrose gradient are enriched in HMG-CoA reductase and cytochrome c oxidase activities. The reductase present in microsomal preparations from the whole adrenal cortex has an apparent Km of 5.6 × 10−5 M for (R,S)-HMG-CoA. Reductase activities found in the microsomal fractions from the zona glomerulosa, the zona fasciculata, and the zona reticularis were 1.32, 7.37, and 9.74 nmol mevalonate formed per milligram protein in 30 min respectively.

scholarly journals Independent regulation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase and chylomicron remnant receptor activities in rat liver

1984 ◽  
Vol 218 (1) ◽  
pp. 203-211 ◽  
Author(s):  
D P Wade ◽  
A K Soutar ◽  
G F Gibbons
Keyword(s):  
Coenzyme A ◽  
Binding Capacity ◽  
Reductase Activity ◽  
Intragastric Administration ◽  
Hmg Coa Reductase ◽  
Liver Membranes ◽  
Coa Reductase ◽  
Chylomicron Remnants ◽  
Coenzyme A Reductase

Treatment of rats with pharmacological doses of oestrogen resulted in a 3-fold decrease in the activity of hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase) and a 4-fold increase in saturable binding of 125I-labelled chylomicron remnants to liver membranes in vitro. Intragastric administration of mevalonolactone to rats did not affect the capacity of the liver membranes to bind to labelled chylomicron remnants even though there was a substantial decrease in the activity of HMG-CoA reductase. Similar results were obtained after cholesterol feeding. Simultaneous treatment of rats with cholestyramine and compactin increased hepatic HMG-CoA reductase activity 6-fold. However, liver membranes derived from these animals showed no change in their capacity to bind to labelled chylomicron remnants in vitro. Administration of mevalonolactone to the cholestyramine/compactin-treated animals also failed to produce a change in remnant-binding capacity. Although administration of mevalonolactone alone produced a significant 3-fold decrease in the activity of hepatic HMG-CoA reductase it was unable to suppress significantly the increase in enzyme activity caused by treatment with cholestyramine and compactin.

scholarly journals 3-Hydroxy-3-methylglutaryl-coenzyme A reductase. A comparison of the modulation in vitro by phosphorylation and dephosphorylation to modulation of enzyme activity by feeding cholesterol- or cholestyramine-supplemented diets

1980 ◽  
Vol 185 (2) ◽  
pp. 435-441 ◽  
Author(s):  
Konstantinos A. Mitropoulos ◽  
Brian L. Knight ◽  
Bernard E. A. Reeves
Keyword(s):  
Microsomal Fraction ◽  
Coenzyme A ◽  
Maximal Activity ◽  
Kinetic Properties ◽  
Standard Diet ◽  
Microsomal Preparation ◽  
Phosphoprotein Phosphatase ◽  
Coa Reductase ◽  
Hydroxymethylglutaryl Coa Reductase ◽  
Coenzyme A Reductase

The activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (hydroxymethylglutaryl-CoA reductase) was considerably inhibited during incubation with ATP+Mg2+. The inactivated enzyme was reactivated on further incubation with partially purified cytosolic phosphoprotein phosphatase. The inactivation was associated with a decrease in the apparent Km of the reductase for hydroxymethylglutaryl-CoA, and this was reversed on reactivation. The slight increase in activity observed during incubation of microsomal fraction without ATP was not associated with a change in apparent Km and, unlike the effect of the phosphatase, was not inhibited by NaF. Liver microsomal fraction from rats given cholesterol exhibited a low activity of hydroxymethylglutaryl-CoA reductase with a low apparent Km for hydroxymethylglutaryl-CoA. Mícrosomal fraction from rats fed cholestyramine exhibited a high activity with a high Km. To discover whether these changes had resulted from phosphorylation and dephosphorylation of the reductase, microsomal fraction from rats fed the supplemented diets and the standard diet were inactivated with ATP and reactivated with phosphoprotein phosphatase. Inactivation reduced the maximal activity of the reductase in each microsomal preparation and also reduced the apparent Km for hydroxymethylglutaryl-CoA. There was no difference between the preparations in the degree of inactivation produced by ATP. Treatment with phosphatase restored both the maximal activity and the apparent Km of each preparation, but never significantly increased the activity above that observed with untreated microsomal fraction. It is concluded that hydroxymethylglutaryl-CoA reductase in microsomal fraction prepared by standard procedures is almost entirely in the dephosphorylated form, and that the difference in kinetic properties in untreated microsomal fraction from rats fed the three diets cannot be explained by differences in the degree of phosphorylation of the enzyme.

scholarly journals A new method for assaying rat liver microsomal 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity and its application in a study of the effect of dietary cholesterol on this effect of dietary cholesterol on this enzyme

1977 ◽  
Vol 164 (3) ◽  
pp. 501-508 ◽  
Author(s):  
Y A Baqir ◽  
R Booth
Keyword(s):  
Rat Liver ◽  
Cholesterol Ester ◽  
Time Course ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Dietary Cholesterol ◽  
New Method ◽  
Coa Reductase ◽  
Microsomal Cholesterol ◽  
Coenzyme A Reductase

A new method suitable for measuring rat liver 3-hydroxy-3-methylglutaryl-CoA reductase activity is described and its advantages over methods previously available are discussed. An accurate time course was measured for the inhibition of liver microsomal 3-hydroxy-3-methylglutaryl-CoA reductase activity by dietary cholesterol; this enzyme was affected 1 1/4 h after the rats began to consume a cholesterol-rich diet. In this experiment there was no correlation between concentrations of microsomal cholesterol ester and the activity of 3-hydroxy-3-methylglutary-CoA reductase.

scholarly journals Genome Sequence of the Fungal Strain 14919 Producing 3-Hydroxy-3-Methylglutaryl–Coenzyme A Reductase Inhibitor FR901512

2017 ◽  
Vol 5 (14) ◽  
Author(s):  
Hiroya Itoh ◽  
Makoto Matsui ◽  
Toshitaka Kumagai ◽  
Masanori Arita ◽  
Masayuki Machida ◽  
...  
Keyword(s):  
Soil Sample ◽  
Genome Sequence ◽  
Reductase Inhibitor ◽  
Coenzyme A ◽  
Fungal Strain ◽  
Hmg Coa Reductase ◽  
Chiba Prefecture ◽  
Hmg Coa Reductase Inhibitor ◽  
Coa Reductase ◽  
Coenzyme A Reductase

ABSTRACT Fungal strain 14919 was originally isolated from a soil sample collected at Mt. Kiyosumi, Chiba Prefecture, Japan. It produces FR901512, a potent and strong 3-hydroxy-3-methylglutaryl–coenzyme A (HMG-CoA) reductase inhibitor. The genome sequence of fungal strain 14919 was determined and annotated to improve the productivity of FR901512.

scholarly journals Inhibition of hydroxymethylglutaryl coenzyme A reductase activity induces a paradoxical increase in DNA synthesis in myeloid leukemia cells

Blood ◽  
1991 ◽  
Vol 77 (5) ◽  
pp. 1064-1070 ◽  
Author(s):  
RJ Hohl ◽  
RA Larson ◽  
V Mannickarottu ◽  
S Yachnin
Keyword(s):  
Dna Synthesis ◽  
Myeloid Leukemia ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Hmg Coa Reductase ◽  
Cellular Dna ◽  
Coa Reductase ◽  
Inhibition Of Dna Synthesis

Abstract The effects of competitive inhibition of hydroxymethylglutaryl coenzyme A (HMG CoA) reductase by compactin on the in vitro proliferation of peripheral blood myeloid leukemia cells were studied using the cells from 45 patients with acute myeloid leukemia or chronic myelogenous leukemia in blast phase. The cells from 58% of these patients showed a dose-related inhibition of DNA synthesis when incubated with compactin. Unexpectedly, cells from 18% of the patients were resistant to the inhibitory effects of compactin on DNA synthesis and responded to the HMG CoA reductase inhibition with an actual increase in the incorporation of 14C-labeled thymidine into DNA. Another 18% of the patients studied displayed both inhibition and stimulation of DNA synthesis in a biphasic response depending on the particular concentration of compactin used. The maximum enhanced rates of cellular DNA synthesis were observed with lower compactin concentrations (5 x 10(-7) mol/L) than were required for maximum inhibition of DNA synthesis (10(-5) mol/L). Leukemia cells displaying a stimulated response to compactin had a significantly lower baseline DNA synthetic rate than did cells that showed an inhibitory response of DNA synthesis to compactin. There was no correlation between these cells' varying DNA synthetic response to compactin and measures of baseline HMG CoA reductase activity or acetate conversion to cholesterol. Whereas the observation of cellular DNA synthesis stimulation by HMG CoA reductase inhibition has not been observed in other mammalian cells and seems paradoxical, explanations may emerge in light of our growing knowledge concerning the importance of isoprenylation for the function of certain cell regulatory proteins.

scholarly journals Activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in brains of adult and 7-day-old rats

1976 ◽  
Vol 154 (2) ◽  
pp. 559-560 ◽  
Author(s):  
M M. Sudjic ◽  
R Booth
Keyword(s):  
Rat Brain ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Cholesterol Biosynthesis ◽  
Adult Brain ◽  
Adult Rat ◽  
Adult Rat Brain ◽  
Old Rats ◽  
Coa Reductase ◽  
Coenzyme A Reductase

Rat brain contains 3-hydroxy-3-methylglutaryl-CoA reductase activity, but this enzyme is far more active in 7-day-old brain than in adult brain. This difference may partly explain why cholesterol biosynthesis is more rapid in growing than in adult rat brain.

scholarly journals 3-Hydroxy-3-methylglutaryl coenzyme A reductase localization in rat liver peroxisomes and microsomes of control and cholestyramine-treated animals: quantitative biochemical and immunoelectron microscopical analyses.

1986 ◽  
Vol 103 (3) ◽  
pp. 875-886 ◽  
Author(s):  
G A Keller ◽  
M Pazirandeh ◽  
S Krisans
Keyword(s):  
Rat Liver ◽  
Coenzyme A ◽  
Specific Activity ◽  
Reductase Activity ◽  
Cholesterol Biosynthesis ◽  
Normal Liver ◽  
Hmg Coa Reductase ◽  
The Matrix ◽  
Coa Reductase ◽  
Liver Peroxisomes

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, a key regulatory enzyme involved in cholesterol biosynthesis, has recently been reported to be present in rat liver peroxisomes (Keller, G.A., M.C. Barton, D.J. Shapiro, and S.J. Singer, 1985, Proc. Natl. Acad. Sci. USA, 82:770-774). Immunoelectron labeling of ultrathin frozen sections of normal liver, using two monoclonal antibodies to purified rat liver microsomal HMG-CoA reductase, indicated that the enzyme is present in the matrix of peroxisomes. This study is a quantitative biochemical and immunoelectron microscopical analysis of HMG-CoA reductase in rat liver peroxisomes and microsomes of normal and cholestyramine-treated animals. Cholestyramine treatment produced a six- to sevenfold increase in the specific activity of peroxisomal HMG-CoA reductase, whereas the microsomal HMG-CoA reductase specific activity increased by about twofold. Using a computer program that calculates optimal linear combinations of marker enzymes, it was determined that between 20 and 30% of the total reductase activity was located in the peroxisomes of cholestyramine-treated animals. Less than 5% of the reductase activity was present in peroxisomes under control conditions. Quantitation of the immunoelectron microscopical data was in excellent agreement with the biochemical results. After cholestyramine treatment there was an eightfold increase in the density of gold particles per peroxisome, and we estimate about a threefold increase in the labeling of the ER.

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