Relationship between 5-Nucleotidase, Adenosine Deaminase, AMP Deaminase, ATP-(Mg^2+)-ase Activities and dTMP Kinase Activity in Rat Liver Mitochondria

Enzyme ◽  
1979 ◽  
Vol 24 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Janusz Greger ◽  
Krystyna Fabianowska
Keyword(s):  
Adenosine Deaminase ◽  
Rat Liver ◽  
Kinase Activity ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Amp Deaminase

scholarly journals Partial purification and properties of rat liver mitochondrial polynucleotide phosphorylase

1972 ◽  
Vol 130 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Y. P. See ◽  
P. S. Fitt
Keyword(s):  
Rat Liver ◽  
Kinase Activity ◽  
Liver Mitochondria ◽  
Partial Purification ◽  
Rat Liver Mitochondria ◽  
Polynucleotide Phosphorylase ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Purification And Properties ◽  
Exchange Activity

1. Polynucleotide phosphorylase was partially purified from the inner membrane of rat liver mitochondria. 2. The partially purified particulate enzyme catalyses phosphorolysis of poly(A), poly(C), poly(U) and RNA to nucleoside diphosphates. 3. It is devoid of nucleoside diphosphate-polymerization activity. 4. Variable amounts of ADP/Pi-exchange activity are associated with the polynucleotide phosphorylase and are probably due to a different enzyme. 5. ADP is the preferred substrate for exchange, and little or no reaction occurs with other nucleoside diphosphates, but ATP/Pi-exchange takes place at one-third the rate observed with ADP. 6. The partially purified enzyme is free from the phosphatases found in the crude mitochondrial inner membrane, but is associated with an endonuclease activity and some adenylate kinase activity; no cytidylate kinase activity analogous to the latter was detectable.

Different Effect Of Dgtp On 2'-Deoxyadenosine Metabolism In Mitochondria And Cytosol

1992 ◽  
Vol 47 (11-12) ◽  
pp. 893-897 ◽  
Author(s):  
Janusz Greger ◽  
Fabianowska-Majewska Krystyna
Keyword(s):  
Physical Properties ◽  
Adenosine Deaminase ◽  
Rat Liver ◽  
Liver Mitochondria ◽  
Subcellular Fractions ◽  
Rat Liver Mitochondria

Two enzymes participating in 2′-deoxyadenosine (dAdo) metabolism: dAdo kinase (dAdoK EC 2.7.1.76) and adenosine deaminase (ADA, EC 3.5.4.4) were partially purified from rat liver mitochondria and cytosol and influence of nucleosides and nucleotides on the activity of these enzymes were investigated. Mitochondrial and cytosol dAdoK are separate proteins, while ADA from both subcellular fractions possesses similar physical properties. dGTP, a com petitive inhibitor of mitochondrial dAdoK, inhibits cytosol ADA in a mixed way but activates mitochondrial ADA and cytosol dAdoK. A possible effect of dGTP on dAdo metabolism in mitochondria and cytosol is discussed

scholarly journals Kinase activator protein mediates longer-term effects of starvation on activity of pyruvate dehydrogenase kinase in rat liver mitochondria

1986 ◽  
Vol 239 (2) ◽  
pp. 347-354 ◽  
Author(s):  
G S Denyer ◽  
A L Kerbey ◽  
P J Randle
Keyword(s):  
Rat Liver ◽  
Pyruvate Dehydrogenase ◽  
Protein Fraction ◽  
Kinase Activity ◽  
Gel Filtration ◽  
Liver Mitochondria ◽  
Pyruvate Dehydrogenase Kinase ◽  
Rat Liver Mitochondria ◽  
Fractional Precipitation ◽  
Activator Protein

Starvation of rats for 48 h increased the activity of PDH (pyruvate dehydrogenase) kinase 2.2-fold in extracts of liver mitochondria, 2.9-fold in PDH complex partially purified therefrom by fractional precipitation, and 5-fold in PDH complex partially purified by gel filtration on Sephacryl S-300. A protein fraction was separated from PDH complex in extracts of rat liver mitochondria by gel filtration or fractional precipitation, which increased the activity of PDH kinase in rat liver and pig heart PDH complexes. The activity of this protein fraction was increased approx. 2.5-fold by 48 h starvation of rats. With highly purified pig heart PDH complex it was shown that the protein fraction increased the Vmax. of the PDH kinase reaction 35-fold (fraction from fed rats) or 82-fold (fraction from starved rats); starvation had no effect on the concentration of protein fraction required to give 0.5 Vmax. Evidence is given that the increase in PDH kinase activity effected in extracts of liver mitochondria by starvation is due to increased activity of kinase activator protein, which is tightly bound by rat liver PDH complex and not removed by a single gel filtration. With pig heart PDH complex, increased PDH kinase activity was retained after gel filtration of an admixture with kinase activator protein from starved rats, but was restored to the control value by a second gel filtration; the alterations in PDH kinase activity were associated with obvious changes in protein bands in SDS gels.

scholarly journals The role of mitochondria in modifying calcium-sensitive cytoplasmic metabolic activities. Modification of pyruvate kinase activity

1972 ◽  
Vol 128 (2) ◽  
pp. 415-420 ◽  
Author(s):  
J. Meli ◽  
F. L. Bygrave
Keyword(s):  
Pyruvate Kinase ◽  
Rat Liver ◽  
Kinase Activity ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Pyruvate Kinase Activity ◽  
Metabolic Activities ◽  
The One

1. The modification of pyruvate kinase activity in vitro was examined by altering the environmental [Mg2+]/[Ca2+] ratio with EDTA on the one hand and isolated rat liver mitochondria on the other. 2. Controlled additions of Ca2+ and EDTA caused pyruvate kinase activity to be alternately and rapidly switched on and off. 3. By being able to accumulate Ca2+ in preference to Mg2+ rat liver mitochondria were able to alter the [Mg2+]/[Ca2+] ratio in the vicinity of pyruvate kinase and thereby modify the activity of this enzyme. 4. The possible role of mitochondria in modifying pyruvate kinase and other ion-sensitive cytoplasmic enzyme activities is discussed.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

Energy and Antioxidant Status of Rat Liver Mitochondria during Hypoxia- Reoxygenation of Different Duration

2016 ◽  
Vol 7 (4) ◽  
pp. 349-361
Author(s):  
Olga A. Gonchar ◽  
Valentina I. Nosar ◽  
Larisa. V. Bratus ◽  
I. N. Tymchenko ◽  
N. N. Steshenko ◽  
...  
Keyword(s):  
Rat Liver ◽  
Antioxidant Status ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Hypoxia Reoxygenation
Sign in / Sign up

Export Citation Format

Share Document