Biomaterial Database

Studies on the effect of copper deficiency on rat liver mitochondria. III. Effects on adenine nucleotide translocase. 1986

N T Davies, and C B Lawrence

Liver mitochondria from Cu-deficient rats exhibit impaired State 3 respiration (oxygen consumption in the presence of exogenous ADP) compared with Cu-adequate controls, whereas State 4 respiration (oxygen consumption after depletion of exogenous ADP) and ADP/O are unaffected. In view of previous observations (Davies, N.T., Lawrence, C.B., Mills, C.F. and Nicol, F. (1985) Biochim. Biophys. Acta 809, 351-361) it seemed that a decline in cytochrome c oxidase activity (EC 1.9.3.1) could not fully account for these findings. Cu deficiency resulted in a significant decline (40%, P less than 0.01) in [14C]ADP uptake by liver mitochondria which suggests there is a reduced activity of the adenine nucleotide translocase. The reduced translocase activity was not associated with any marked change in fatty-acid composition of either intact mitochondria or inner mitochondrial membranes. Inhibitor titrations with the irreversible inhibitor carboxyatractyloside showed that 'Cu-deficient' mitochondria required the same concentration of inhibitor to produce 100% inhibition of State 3 respiration as control mitochondria, suggesting that the amount of functional translocase enzyme present is unaffected. When the translocase assay was allowed to proceed until equilibrium was established between external and internal nucleotides, it was apparent that the exchangeable adenine nucleotide pool of Cu-deficient mitochondria was 36% lower than in controls. Analysis of mitochondria for their ATP, ADP and AMP contents showed that, whereas the AMP content was unaffected, ATP and ADP contents were 39 and 40% lower, respectively, which resulted in a significantly reduced pool of total adenine nucleotides (ATP + ADP + AMP) and a reduced 'energy charge' [(ATP + 0.5 ADP)/(ATP + ADP + AMP)]. These results are discussed in relation to current concepts of the regulation and control of mitochondrial respiration.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008930	Mitochondria, Liver	Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)	Liver Mitochondria,Liver Mitochondrion,Mitochondrion, Liver
D009713	Nucleotidyltransferases	A class of enzymes that transfers nucleotidyl residues. EC 2.7.7.	Nucleotidyltransferase
D010085	Oxidative Phosphorylation	Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.	Phosphorylation, Oxidative,Oxidative Phosphorylations,Phosphorylations, Oxidative
D003300	Copper	A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.	Copper-63,Copper 63
D003576	Electron Transport Complex IV	A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.	Cytochrome Oxidase,Cytochrome aa3,Cytochrome-c Oxidase,Cytochrome Oxidase Subunit III,Cytochrome a,a3,Cytochrome c Oxidase Subunit VIa,Cytochrome-c Oxidase (Complex IV),Cytochrome-c Oxidase Subunit III,Cytochrome-c Oxidase Subunit IV,Ferrocytochrome c Oxygen Oxidoreductase,Heme aa3 Cytochrome Oxidase,Pre-CTOX p25,Signal Peptide p25-Subunit IV Cytochrome Oxidase,Subunit III, Cytochrome Oxidase,p25 Presequence Peptide-Cytochrome Oxidase,Cytochrome c Oxidase,Cytochrome c Oxidase Subunit III,Cytochrome c Oxidase Subunit IV,Oxidase, Cytochrome,Oxidase, Cytochrome-c,Signal Peptide p25 Subunit IV Cytochrome Oxidase,p25 Presequence Peptide Cytochrome Oxidase
D005227	Fatty Acids	Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)	Aliphatic Acid,Esterified Fatty Acid,Fatty Acid,Fatty Acids, Esterified,Fatty Acids, Saturated,Saturated Fatty Acid,Aliphatic Acids,Acid, Aliphatic,Acid, Esterified Fatty,Acid, Saturated Fatty,Esterified Fatty Acids,Fatty Acid, Esterified,Fatty Acid, Saturated,Saturated Fatty Acids
D000226	Mitochondrial ADP, ATP Translocases	A class of nucleotide translocases found abundantly in mitochondria that function as integral components of the inner mitochondrial membrane. They facilitate the exchange of ADP and ATP between the cytosol and the mitochondria, thereby linking the subcellular compartments of ATP production to those of ATP utilization.	ADP,ATP Carrier,ADP,ATP Translocator Protein,Adenine Nucleotide Translocase,ADP Translocase,ATP Translocase,ATP,ADP-Carrier,ATP-ADP Translocase,Adenine Nucleotide Carrier (Mitochondrial),Mitochondrial ADP-ATP Carriers,ADP-ATP Carriers, Mitochondrial,Mitochondrial ADP ATP Carriers
D000227	Adenine Nucleotides		Adenine Nucleotide,Adenosine Phosphate,Adenosine Phosphates,Nucleotide, Adenine,Nucleotides, Adenine,Phosphate, Adenosine,Phosphates, Adenosine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia