The adenine nucleotide translocator in foetal, suckling and adult rat liver mitochondria

The effect of the local anaesthetic, butacaine, on adenine nucleotide binding and translocation in rat liver mitochondria partially depleted of their adenine nucleotide content was investigated. The range of butacaine concentrations that inhibit adenine nucleotide translocation and the extent of the inhibition are similar to the values obtained for native mitochondria. Butacaine does not alter either the total number of atractyloside-sensitive binding sites of depleted mitochondria, or the affinity of these sites for ADP or ATP under conditions where a partial inhibition of the rate of adenine nucleotide translocation is observed. The data are consistent with an effect of butacaine on the process by which adenine nucleotides are transported across the mitochondrial inner membrane rather than on the binding of adenine nucleotides to sites on the adenine nucleotide carrier. The results are briefly discussed in relation to the use of local anaesthetics in investigations of the mechanism of adenine nucleotide translocation.

Download Full-text

Appearance of Energy Conservation System in Rat Liver Mitochondria during DevelopmentThe Role of Adenine Nucleotide Translocation

The Journal of Biochemistry ◽

10.1093/oxfordjournals.jbchem.a130096 ◽

1973 ◽

Keyword(s):

Energy Conservation ◽

Rat Liver ◽

Adenine Nucleotide ◽

Liver Mitochondria ◽

Rat Liver Mitochondria

Download Full-text

Thyroid-hormone control of state-3 respiration in isolated rat liver mitochondria

Biochemical Journal ◽

10.1042/bj2650731 ◽

1990 ◽

Vol 265 (3) ◽

pp. 731-734 ◽

Cited By ~ 49

Author(s):

R P Hafner ◽

G C Brown ◽

M D Brand

Keyword(s):

Thyroid Hormone ◽

Atp Synthase ◽

Adenine Nucleotide ◽

Liver Mitochondria ◽

Proton Leak ◽

Rat Liver Mitochondria ◽

Protonmotive Force ◽

Adenine Nucleotide Translocator ◽

Hormone Control ◽

Kinetics Of

Oxidative phosphorylation can be treated as two groups of reactions; those that generate protonmotive force (dicarboxylate carrier, succinate dehydrogenase and the respiratory chain) and those that consume protonmotive force (adenine nucleotide and phosphate carriers. ATP synthase and proton leak). Mitochondria from hypothyroid rats have lower rates of respiration in the presence of ADP (state 3) than euthyroid controls. We show that the kinetics of the protonmotive-force generators are unchanged in mitochondria from hypothyroid animals, but the kinetics of the protonmotive-force consumers are altered, supporting proposals that the important effects of thyroid hormone on state 3 are on the ATP synthase or the adenine nucleotide translocator.

Download Full-text

Hepatic ketogenesis in newborn pigs is limited by low mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase activity

Biochemical Journal ◽

10.1042/bj2980207 ◽

1994 ◽

Vol 298 (1) ◽

pp. 207-212 ◽

Cited By ~ 35

Author(s):

P H Duée ◽

J P Pégorier ◽

P A Quant ◽

C Herbin ◽

C Kohl ◽

...

Keyword(s):

Rat Liver ◽

Liver Mitochondria ◽

Oxidation Products ◽

Rat Liver Mitochondria ◽

Acid Oxidation ◽

Acetyl Coa ◽

Pig Liver ◽

Adult Rat ◽

Malonyl Coa ◽

Cpt I

In newborn-pig hepatocytes, the rate of oleate oxidation is extremely low, despite a very low malonyl-CoA concentration. By contrast, the sensitivity of carnitine palmitoyltransferase (CPT) I to malonyl-CoA inhibition is high, as suggested by the very low concentration of malonyl-CoA required for 50% inhibition of CPT I (IC50). The rates of oleate oxidation and ketogenesis are respectively 70 and 80% lower in mitochondria isolated from newborn-pig liver than from starved-adult-rat liver mitochondria. Using polarographic measurements, we showed that the oxidation of oleoyl-CoA and palmitoyl-L-carnitine is very low when the acetyl-CoA produced is channelled into the hydroxymethylglutaryl-CoA (HMG-CoA) pathway by addition of malonate. In contrast, the oxidation of the same substrates is high when the acetyl-CoA produced is directed towards the citric acid cycle by addition of malate. We demonstrate that the limitation of ketogenesis in newborn-pig liver is due to a very low amount and activity of mitochondrial HMG-CoA synthase as compared with rat liver mitochondria, and suggest that this could promote the accumulation of acetyl-CoA and/or beta-oxidation products that in turn would decrease the overall rate of fatty acid oxidation in newborn- and adult-pig livers.

Download Full-text

The kinetic properties of citrate synthase from rat liver mitochondria

Biochemical Journal ◽

10.1042/bj1140597 ◽

1969 ◽

Vol 114 (3) ◽

pp. 597-610 ◽

Cited By ~ 226

Author(s):

D. Shepherd ◽

P. B. Garland

Keyword(s):

Rat Liver ◽

Citrate Synthase ◽

Adenine Nucleotide ◽

Sedimentation Coefficient ◽

Liver Mitochondria ◽

Rat Liver Mitochondria ◽

Kinetic Properties ◽

Acetyl Coa ◽

Ph Optimum ◽

Michaelis Constants

1. Citrate synthase (EC 4.1.3.7) was purified 750-fold from rat liver. 2. Measurements of the Michaelis constants for the substrates of citrate synthase gave values of 16μm for acetyl-CoA and 2μm for oxaloacetate. Each value is independent of the concentration of the other substrate. 3. The inhibition of citrate synthase by ATP, ADP and AMP is competitive with respect to acetyl-CoA. With respect to oxaloacetate the inhibition by AMP is competitive, but the inhibition by ADP and ATP is mixed, being partially competitive. 4. At low concentrations of both substrates the inhibition by ATP is sigmoidal and a Hill plot exhibits a slope of 2·5. 5. The pH optimum of the enzyme is 8·7, and is not significantly affected by ATP. 6. Mg2+ inhibits citrate synthase slightly, but relieves the inhibition caused by ATP in a complex manner. 7. At constant total adenine nucleotide concentration made up of various proportions of ATP, ADP and AMP, the activity of citrate synthase is governed by the concentration of the sum of the energy-rich phosphate bonds of ADP and ATP. 8. The sedimentation coefficient of the enzyme, as measured by activity sedimentation, is 6·3s, equivalent to molecular weight 95000.

Download Full-text