The Role of Compartmentation in the Control of Glycolysis

Ottaway, J. H.; Mowbray, John

doi:10.1016/b978-0-12-152812-6.50010-x

Cited by 159 publications

(69 citation statements)

References 350 publications

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“…The second assumption is supported by calculations based on the values for the rates of spontaneous anomerization of F6P and FBP in vitro [t3,14] and the concentrations of these sugar phosphates and activities of PFK and FBPase in vivo [29,30]. The rates of anomerization reported at 25°C were arbitrarily multiplied by 3 to obtain the approximate rate at 37°C.…”

Section: Assumptions and Supporting Evidencementioning

confidence: 99%

“…Our proposal that anomeric specificities of PFK and FBPase can produce a nonequilibrium distribution of the anomers of F6P and FBP is supported by a computer simulation study [38] based on the in vitro measurements of anomer concentrations and anomerization rates [8][9][10]13,14] corrected to 37°C, and in vivo measurements of F6P and FBP concentrations as well as PFK and FBPase activities [29,30]. In this study, we [38] have shown that the extent of perturbation from anomeric equilibrium is dependent on the activities of PFK and FBPase as well as the total amount of fructose phosphate present in the system.…”

Section: Further Evidence For the Modelmentioning

confidence: 99%

“…As such the enzyme pair becomes analogous to immobilized, coupled enzymes. In such immobilized systems there is ample evidence [29] that substrate and product concentrations within the boundary of the adsorbed complex are maintained.at a level far from their equilibrium concentrations outside the boundary (e.g., in the cytosol). Thus, even if one assumes that PGI and ALD do have anomerase activity in vivo, they would have negligible effect on the anomerization of F6P and FBP inside the complex as long as they are not components thereof.…”

Section: Assumptions and Supporting Evidencementioning

confidence: 99%

“…Based on this evidence, we can envision that the active-sites of both enzymes are as close as 100 •. Taking the diffusion coefficient within the enzyme complex to be 10 -8 cmZ/s [29], then the transit time of F6P and FBP between active sites would be more than 103 208 times shorter than the half-life of their spontaneous anomerization.…”

Section: Assumptions and Supporting Evidencementioning

confidence: 99%

“…In this study, we [38] have shown that the extent of perturbation from anomeric equilibrium is dependent on the activities of PFK and FBPase as well as the total amount of fructose phosphate present in the system. For example, in rat liver (pH 7.4, 37°C), for which PFK activity is 3.3 #mol/min/g wet wt and FBPase activity 15 #mol/min/g wet wt [30] and the total equilibrated fructose phosphate 40 nmol/ g wet wt [29], the/3/a ratio is 2.2 for F6P and 86 for FBP, instead of the equilibrium ratio of 4.0 [9]. The experimental confirmation of the results of these simulations has to await the surmounting of certain technical difficulties.…”

Section: Further Evidence For the Modelmentioning

confidence: 99%

See 4 more Smart Citations

A proposed model for the regulation of phosphofructokinase and fructose 1,6‐bisphosphatase based on their reciprocal anomeric specificities

Koerner¹,

Voll²,

Younathan³

1977

FEBS Letters

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Section: Assumptions and Supporting Evidencementioning

confidence: 99%

Section: Further Evidence For the Modelmentioning

confidence: 99%

Section: Assumptions and Supporting Evidencementioning

confidence: 99%

Section: Assumptions and Supporting Evidencementioning

confidence: 99%

Section: Further Evidence For the Modelmentioning

confidence: 99%

See 3 more Smart Citations

A proposed model for the regulation of phosphofructokinase and fructose 1,6‐bisphosphatase based on their reciprocal anomeric specificities

Koerner¹,

Voll²,

Younathan³

1977

FEBS Letters

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Integrated and Organized Cellular Energetic Systems

Saks

Monge

Guzun

et al. 2009

Wiley Encyclopedia of Chemical Biology

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Bioenergetics as a part of biophysical chemistry and biophysics is a quantitative science that is based on several fundamental theories. The definition of energy itself is given by the first law of thermodynamics, and application of the second law of thermodynamics shows that the living cells can only function as open systems in which internal order (low entropy state) is maintained by increasing the entropy in surrounding medium (Schrödinger's principle of negentropy). For this mechanism, exchange of mass is needed that yields metabolism as the sum of catabolism and anabolism. The free‐energy changes taking place during metabolic reactions obey rules of chemical thermodynamics, which deals with Gibbs free energy of chemical reactions and with electrochemical potentials. For application of these theories to the integrated systems in vivo , complex cellular organization should be accounted for: macromolecular crowding, metabolic channeling and functional coupling mechanisms caused by close and tight protein–protein interactions, compartmentation of enzymes, as well as both macrocompartmentation and microcompartmentation of substrates and metabolites in cells should be considered. For integration of these system components, effective methods of communication, including compartmentalized energy transfer systems, are required. These systems are represented in muscle cells by phosphotransfer networks, mostly by creatine kinase and adenylate kinase systems. System analysis of these networks shows their central role both in energy transfer and metabolic feedback regulation of mitochondrial function, in regulation of ion fluxes and cellular energetics during increased workload by synchronizing the cellular electrical and mechanical activities with energy supply and substrate oxidation.

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Integrated and Organized Cellular Energetic Systems: Theories of Cell Energetics, Compartmentation, and Metabolic Channeling

Saks

Monge

Anmann

et al. 2007

Molecular System Bioenergetics

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Bioenergetics as a part of biophysical chemistry and biophysics is a quantitative science that is based on several fundamental theories. The definition of energy itself is given by the first law of thermodynamics, and application of the second law of thermodynamics shows that living cells can function as open systems only where the internal order (low entropy state) is maintained due to increasing the entropy in the surrounding medium (Schrödinger's principle of negentropy). For this, the exchange of mass is needed, which gives rise to metabolism as the sum of catabolism and anabolism, and the free energy changes during catabolic reactions supply energy for all cellular work -osmotic, mechanical, and biochemical. The free energy changes during metabolic reactions obey the rules of chemical thermodynamics, which deals with Gibbs free energy of chemical reactions and with electrochemical potentials. For application of these theories to the integrated systems in vivo, complex cellular organization should be accounted for: macromolecular crowding; metabolic channeling and functional coupling mechanisms due to close and tight protein-protein interactions; compartmentation of the enzymes due to their attachment to the subcellular membranes or connection to the cytoskeleton; and both macro-and microcompartmentation of substrates and metabolites in the cells. Because of this, almost all processes important for cell life are localized within small areas of the cell, and for their integration effective systems of communication, including compartmentalized energy transfer systems, are required. These are represented in muscle cells by the phosphotransfer networks, mostly by the creatine kinase and adenylate kinase systems, whose alterations under ischemic conditions contribute significantly to acute ischemic contractile failure of the heart. 59 Molecular System Bioenergetics: Energy for Life. Edited by Valdur Saks

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The Role of Compartmentation in the Control of Glycolysis

Cited by 159 publications

References 350 publications

A proposed model for the regulation of phosphofructokinase and fructose 1,6‐bisphosphatase based on their reciprocal anomeric specificities

A proposed model for the regulation of phosphofructokinase and fructose 1,6‐bisphosphatase based on their reciprocal anomeric specificities

Integrated and Organized Cellular Energetic Systems

Integrated and Organized Cellular Energetic Systems: Theories of Cell Energetics, Compartmentation, and Metabolic Channeling

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