Timohhina 2009 J Bioenerg Biomembr
| Timohhina N, Guzun R, Tepp K, Monge C, Varikmaa M, Vija H, Sikk P, Kaambre T, Sackett D, Saks V (2009) Direct measurement of energy fluxes from mitochondria into cytoplasm in permeabilized cardiac cells in situ: some evidence for mitochondrial interactosome. J. Bioenerg. Biomembr. 41: 259-275. |
Timohhina N, Guzun R, Tepp K, Monge C, Varikmaa M, Vija H, Sikk P, Kaambre T, Sackett D, Saks V (2009) J. Bioenerg. Biomembr.
Abstract: The aim of this study was to measure energy fluxes from mitochondria in isolated permeabilized cardiomyocytes. Respiration of permeabilized cardiomyocytes and mitochondrial membrane potential were measured in presence of MgATP, pyruvate kinase - phosphoenolpyruvate and creatine. ATP and phosphocreatine concentrations in medium surrounding cardiomyocytes were determined. While ATP concentration did not change in time, mitochondria effectively produced phosphocreatine (PCr) with PCr/O2 ratio equal to 5.68 +/- 0.14. Addition of heterodimeric tubulin to isolated mitochondria was found to increase apparent Km for exogenous ADP from 11 +/- 2 µM to 330 +/- 47 µM, but creatine again decreased it to 23 +/- 6 µM. These results show directly that under physiological conditions the major energy carrier from mitochondria into cytoplasm is PCr, produced by mitochondrial creatine kinase (MtCK), which functional coupling to adenine nucleotide translocase is enhanced by selective limitation of permeability of mitochondrial outer membrane within supercomplex ATP Synthasome-MtCK-VDAC-tubulin, Mitochondrial Interactosome. • Keywords: Respiration, cardiomyocytes, mitochondria, ceatine kinase, creatine, phosphocreatine, tubulin
• O2k-Network Lab: EE_Tallinn_Saks VA, FR_Grenoble_Saks VA
Labels:
Organism: Human
Tissue;cell: Cardiac Muscle"Cardiac Muscle" is not in the list (Heart, Skeletal muscle, Nervous system, Liver, Kidney, Lung;gill, Islet cell;pancreas;thymus, Endothelial;epithelial;mesothelial cell, Blood cells, Fat, ...) of allowed values for the "Tissue and cell" property.
Preparation: Permeabilized Cell or Tissue; Homogenate"Permeabilized Cell or Tissue; Homogenate" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property.
HRR: Oxygraph-2k
