Guzun 2009 Biochim Biophys Acta: Difference between revisions
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{{Publication | {{Publication | ||
|title=Guzun R, Timohhina N, Tepp K, Monge C, Kaambre T, Sikk P, Kuznetsov AV, Pison C, Saks V (2009) Regulation of respiration controlled by mitochondrial creatine kinase in permeabilized cardiac cells in situ. Importance of system level properties. Biochim Biophys Acta 1787: 1089- | |title=Guzun R, Timohhina N, Tepp K, Monge C, Kaambre T, Sikk P, Kuznetsov AV, Pison C, Saks V (2009) Regulation of respiration controlled by mitochondrial creatine kinase in permeabilized cardiac cells in situ. Importance of system level properties. Biochim Biophys Acta 1787:1089-105. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/19362066 PMID: 19362066] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/19362066 PMID: 19362066 Open Access] | ||
|authors=Guzun R, Timohhina N, Tepp K, Monge C, Kaambre T, Sikk P, Kuznetsov AV, Pison C, Saks V | |authors=Guzun R, Timohhina N, Tepp K, Monge C, Kaambre T, Sikk P, Kuznetsov AV, Pison C, Saks V | ||
|year=2009 | |year=2009 | ||
|journal=Biochim Biophys Acta | |journal=Biochim Biophys Acta | ||
|abstract=The main focus of this investigation is steady state kinetics of regulation of mitochondrial respiration in permeabilized cardiomyocytes in situ. Complete kinetic analysis of the regulation of respiration by mitochondrial creatine kinase was performed in the presence of pyruvate kinase and phosphoenolpyruvate to simulate interaction of mitochondria with glycolytic enzymes. Such a system analysis revealed striking differences in kinetic behaviour of the MtCK-activated mitochondrial respiration in situ and in vitro. Apparent dissociation constants of MgATP from its binary and ternary complexes with MtCK, K<sub>ia</sub> and K<sub>a</sub> (1.94 ยฑ 0.86 mM and 2.04 ยฑ 0.14 mM, correspondingly) were increased by several orders of magnitude ''in situ'' in comparison with same constants ''in vitro'' (0.44 ยฑ 0.08 mM and 0.016 ยฑ 0.01 mM, respectively). Apparent dissociation constants of creatine, K<sub>ib</sub> and K<sub>b</sub> (2.12 ยฑ 0.21 mM 2.17 ยฑ 0.40 Mm, correspondingly) were significantly decreased ''in situ'' in comparison with ''in vitro'' mitochondria (28 ยฑ 7 mM and 5 ยฑ 1.2 mM, respectively). Dissociation constant for phosphocreatine was not changed. These data may indicate selective restriction of metabolites diffusion at the level of mitochondrial outer membrane. It is concluded that mechanisms of the regulation of respiration and energy fluxes in vivo are system level properties which depend on intracellular interactions of mitochondria with cytoskeleton, intracellular MgATPases and cytoplasmic glycolytic system. | |abstract=The main focus of this investigation is steady state kinetics of regulation of mitochondrial respiration in permeabilized cardiomyocytes in situ. Complete kinetic analysis of the regulation of respiration by mitochondrial creatine kinase was performed in the presence of pyruvate kinase and phosphoenolpyruvate to simulate interaction of mitochondria with glycolytic enzymes. Such a system analysis revealed striking differences in kinetic behaviour of the MtCK-activated mitochondrial respiration in situ and ''in vitro''. Apparent dissociation constants of MgATP from its binary and ternary complexes with MtCK, K<sub>ia</sub> and K<sub>a</sub> (1.94 ยฑ 0.86 mM and 2.04 ยฑ 0.14 mM, correspondingly) were increased by several orders of magnitude ''in situ'' in comparison with same constants ''in vitro'' (0.44 ยฑ 0.08 mM and 0.016 ยฑ 0.01 mM, respectively). Apparent dissociation constants of creatine, K<sub>ib</sub> and K<sub>b</sub> (2.12 ยฑ 0.21 mM 2.17 ยฑ 0.40 Mm, correspondingly) were significantly decreased ''in situ'' in comparison with ''in vitro'' mitochondria (28 ยฑ 7 mM and 5 ยฑ 1.2 mM, respectively). Dissociation constant for phosphocreatine was not changed. These data may indicate selective restriction of metabolites diffusion at the level of mitochondrial outer membrane. It is concluded that mechanisms of the regulation of respiration and energy fluxes ''in vivo'' are system level properties which depend on intracellular interactions of mitochondria with cytoskeleton, intracellular MgATPases and cytoplasmic glycolytic system. | ||
|keywords=Respiration, Cardiomyocyte, Mitochondria, Creatine kinase,ย Creatine | |keywords=Respiration, Cardiomyocyte, Mitochondria, Creatine kinase,ย Creatine | ||
|mipnetlab= | |mipnetlab=EE Tallinn Saks VA, FR Grenoble Saks VA, EE Tallinn Kaambre T, FR Grenoble Schlattner U | ||
|discipline=Mitochondrial Physiology, Biomedicine | |discipline=Mitochondrial Physiology, Biomedicine | ||
}} | }} | ||
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|tissues=Heart | |tissues=Heart | ||
|preparations=Intact cells | |preparations=Intact cells | ||
|topics=Ion | |topics=ADP, Ion;substrate transport, PCr;Cr, Redox state, Substrate | ||
|couplingstates=OXPHOS | |couplingstates=OXPHOS | ||
|instruments=Oxygraph-2k | |instruments=Oxygraph-2k | ||
|discipline=Mitochondrial Physiology, Biomedicine | |discipline=Mitochondrial Physiology, Biomedicine | ||
}} | }} |
Latest revision as of 14:32, 20 March 2015
Guzun R, Timohhina N, Tepp K, Monge C, Kaambre T, Sikk P, Kuznetsov AV, Pison C, Saks V (2009) Regulation of respiration controlled by mitochondrial creatine kinase in permeabilized cardiac cells in situ. Importance of system level properties. Biochim Biophys Acta 1787:1089-105. |
Guzun R, Timohhina N, Tepp K, Monge C, Kaambre T, Sikk P, Kuznetsov AV, Pison C, Saks V (2009) Biochim Biophys Acta
Abstract: The main focus of this investigation is steady state kinetics of regulation of mitochondrial respiration in permeabilized cardiomyocytes in situ. Complete kinetic analysis of the regulation of respiration by mitochondrial creatine kinase was performed in the presence of pyruvate kinase and phosphoenolpyruvate to simulate interaction of mitochondria with glycolytic enzymes. Such a system analysis revealed striking differences in kinetic behaviour of the MtCK-activated mitochondrial respiration in situ and in vitro. Apparent dissociation constants of MgATP from its binary and ternary complexes with MtCK, Kia and Ka (1.94 ยฑ 0.86 mM and 2.04 ยฑ 0.14 mM, correspondingly) were increased by several orders of magnitude in situ in comparison with same constants in vitro (0.44 ยฑ 0.08 mM and 0.016 ยฑ 0.01 mM, respectively). Apparent dissociation constants of creatine, Kib and Kb (2.12 ยฑ 0.21 mM 2.17 ยฑ 0.40 Mm, correspondingly) were significantly decreased in situ in comparison with in vitro mitochondria (28 ยฑ 7 mM and 5 ยฑ 1.2 mM, respectively). Dissociation constant for phosphocreatine was not changed. These data may indicate selective restriction of metabolites diffusion at the level of mitochondrial outer membrane. It is concluded that mechanisms of the regulation of respiration and energy fluxes in vivo are system level properties which depend on intracellular interactions of mitochondria with cytoskeleton, intracellular MgATPases and cytoplasmic glycolytic system. โข Keywords: Respiration, Cardiomyocyte, Mitochondria, Creatine kinase, Creatine
โข O2k-Network Lab: EE Tallinn Saks VA, FR Grenoble Saks VA, EE Tallinn Kaambre T, FR Grenoble Schlattner U
Labels:
Organism: Rat
Tissue;cell: Heart
Preparation: Intact cells
Regulation: ADP, Ion;substrate transport, PCr;Cr, Redox state, Substrate Coupling state: OXPHOS
HRR: Oxygraph-2k