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Bergman C, Kashiwaya Y, Veech RL. The effect of pH and free Mg2+ on ATP linked enzymes and the calculation of Gibbs free energy of ATP hydrolysis. J Phys Chem B 2010; 114:16137-46. [PMID: 20866109 DOI: 10.1021/jp105723r] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The apparent equilibrium constants, K′, of biochemical reactions containing substrates which bind [Mg2+] unequally can be significantly altered by changes in free intracellular [Mg2+]. Intracellular free [Mg2+] can be estimated by measurements of [citrate]/[isocitrate], a ratio known to vary with tissue free [Mg2+]. The combined equilibrium constant for glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, and triose phosphate isomerase for the three reactions (K(GG-TPI)′) was corrected using new binding constants for dihydroxyacetone-phosphate and 3-phosphoglycerate. The result of this calculation is demonstrated in the calculation of the free energy of ATP hydrolysis. In addition, the dependence of the equilibrium constant for the glutamine synthetase reaction on pH and free [Mg2+] was demonstrated. Furthermore, a theory linking the ΔG′ value of mitochondrial complex I−II and the cytosolic ΔG′ value of ATP hydrolysis is discussed with evidence from previous publications.
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Affiliation(s)
- Christian Bergman
- Laboratory of Metabolic Control, NIAAA, NIH, DHHS, 5625 Fishers Lane, Bethesda, Maryland 20892, USA
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Krebs HA, Eggleston LV, Kleinzeller A, Smyth DH. The fate of oxaloacetate in animal tissues. Biochem J 2006; 34:1234-40. [PMID: 16747307 PMCID: PMC1265404 DOI: 10.1042/bj0341234] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- H A Krebs
- The Department of Biochemistry, University of Sheffield
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Krebs HA, Eggleston LV. Biological synthesis of oxaloacetic acid from pyruvic acid and carbon dioxide: The mechanism of carbon dioxide fixation in propionic acid bacteria. Biochem J 2006; 35:676-87. [PMID: 16747435 PMCID: PMC1265544 DOI: 10.1042/bj0350676] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- H A Krebs
- The Department of Biochemistry, University of Sheffield
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Krebs HA, Eggleston LV. Micro-determination of isocitric and cis-aconitic acids in biological material. Biochem J 2006; 38:426-37. [PMID: 16747829 PMCID: PMC1258123 DOI: 10.1042/bj0380426] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- H A Krebs
- Department of Biochemistry, University of Sheffield
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Affiliation(s)
- A Kleinzeller
- The Department of Biochemistry, University of Sheffield
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Krebs HA, Eggleston LV. Biological synthesis of oxaloacetic acid from pyruvic acid and carbon dioxide. Biochem J 2006; 34:1383-95. [PMID: 16747268 PMCID: PMC1265425 DOI: 10.1042/bj0341383] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- H A Krebs
- The Department of Biochemistry, University of Sheffield
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NOSSAL PM. Estimation of L-malate and fumarate by malic decarboxylase of Lactobacillus arabinosus. Biochem J 2004; 50:349-55. [PMID: 14915956 PMCID: PMC1197659 DOI: 10.1042/bj0500349] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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CONWAY EJ, BRADY TG. Biological production of acid and alkali; quantitative relations of succinic and carbonic acids to the potassium and hydrogen ion exchange in fermenting yeast. Biochem J 2004; 47:360-9. [PMID: 14800894 PMCID: PMC1275220 DOI: 10.1042/bj0470360] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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SENTHESHANMUGANATHAN S, ELSDEN SR. The mechanism of the formation of tyrosol by Saccharomyces cerevisiae. Biochem J 2000; 69:210-8. [PMID: 13546168 PMCID: PMC1196540 DOI: 10.1042/bj0690210] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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HASLAM RJ, KREBS HA. Substrate competition in the respiration of animal tissues. The metabolic interactions of pyruvate and alpha-oxoglutarate in rat-liver homogenates. Biochem J 1998; 86:432-46. [PMID: 13960888 PMCID: PMC1201777 DOI: 10.1042/bj0860432] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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CONWAY EJ, ARMSTRONG WM. The total intracellular concentration of solutes in yeast and other plant cells and the distensibility of the plant-cell wall. Biochem J 1998; 81:631-9. [PMID: 13881017 PMCID: PMC1243389 DOI: 10.1042/bj0810631] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
1. The effects of adenine nucleotides on pyruvate metabolism by isolated liver cells and isolated mitochondria have been investigated. The amount of pyruvate carboxylated has been estimated by determining the tricarboxylic acid-cycle intermediates, glutamate and aspartate accumulating in the incubation medium. The extent of pyruvate oxidation has been assessed by measuring oxygen uptake and the yield of (14)CO(2) from [1-(14)C]pyruvate and [2-(14)C]pyruvate. 2. When catalytic amounts of adenine nucleotides (1-2mm) were added to suspensions of isolated liver cells incubated with pyruvate an ATP:ADP ratio greater than 6:1 was maintained. Both pyruvate oxidation to acetyl-CoA and the oxidation of acetyl-CoA through the tricarboxylic acid cycle were stimulated but pyruvate carboxylation was not affected. The production of acetyl-CoA exceeded the capacity of the cells for the oxidation of acetyl-CoA and the excess was converted into ketone bodies. 3. If a low ATP:ADP ratio was maintained in isolated cells or mitochondria by incubating them with dinitrophenol or hexokinase, pyruvate carboxylation was grossly inhibited, oxygen uptake depressed and ketone-body formation stimulated. Measurement of oxaloacetate concentrations confirmed that under these conditions oxaloacetate was rate-limiting for the oxidation of acetyl-CoA via the tricarboxylic acid cycle. The inclusion in the incubation medium of fumarate (1.25mm) completely prevented the ketogenic action of dinitrophenol or hexokinase. 4. When ADP (5mm) was added to a suspension of isolated liver cells incubated with pyruvate an actual ADP concentration of about 1mm was attained. This brought about effects on pyruvate metabolism similar to those obtained with dinitrophenol or hexokinase. 5. These results support the concept that the relative concentrations of adenine nucleotides within the liver cell may play a role in governing the rates of pyruvate oxidation and carboxylation. In addition, they provide further evidence that the availability of oxaloacetate in the liver cell can play a key role in determining whether acetyl-CoA arising from pyruvate is oxidized through the tricarboxylic acid cycle or converted into ketone bodies.
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Alberty RA, Goldberg RN. Calorimetric determination of the standard transformed enthalpy of a biochemical reaction at specified pH and pMg. Biophys Chem 1993; 47:213-23. [PMID: 8241417 DOI: 10.1016/0301-4622(93)80046-l] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In a biochemical reaction there is generally a change in the binding of hydrogen ions and metal ions. Therefore, calorimetric measurements of enthalpies of reaction have to be adjusted for the enthalpies of reaction of the hydrogen ions and metal ions produced or consumed with the buffer. It can be shown that this yields the standard transformed enthalpy of reaction that determines the change in the apparent equilibrium constant K' (written in terms of sums of concentrations of species of a reactant) with temperature at the chosen pH and concentration of free metal ion. The derivations are based on the assumption that the changes in pH and free metal ion concentrations in the calorimetric experiment are small. This assumption is experimentally realized if a solution is well buffered for hydrogen and metal ions. The derived equations are discussed in terms of the implications they have for the performance and interpretation of calorimetric measurements.
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Affiliation(s)
- R A Alberty
- Chemistry Department, Massachusetts Institute of Technology, Cambridge 02139
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Abstract
The thermodynamics of the conversion of aqueous fumarate to L-(-)-malate has been investigated using both heat conduction microcalorimetry and a gas chromatographic method for determining equilibrium constants. The reaction was carried out in aqueous Tris-HCl buffer over the pH range 6.3-8.0, the temperature range 25-47 degrees C, and at ionic strengths varying from 0.0005 to 0.62 mol kg-1. Measured enthalpies and equilibrium ratios have been adjusted to zero ionic strength and corrected for ionization effects to obtain the following standard state values for the conversion of aqueous fumarate 2- to malate 2- at 25 degrees C: K = 4.20 +/- 0.05, delta G degrees = -3557 +/- 30 J mol-1, delta H degrees = -15670 +/- 150 J mol-1, and delta C degrees p = -36 +/- J mol-1 K-1. Equations are given which allow one to calculate the combined effects of pH and temperature on equilibrium constants and enthalpies of this reaction.
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Smith RM, Osborne-White WS, Russell GR. Metabolism of propionate by sheep liver. Pathway of propionate metabolism in aged homogenate and mitochondria. Biochem J 1967; 104:441-9. [PMID: 6048786 PMCID: PMC1270605 DOI: 10.1042/bj1040441] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Experiments were conducted with aged nuclear-free homogenate of sheep liver and aged mitochondria in an attempt to measure both the extent of oxidation of propionate and the distribution of label from [2-(14)C]propionate in the products. With nuclear-free homogenate, propionate was 44% oxidized with the accumulation of succinate, fumarate, malate and some citrate. Recovery of (14)C in these intermediates and respiratory carbon dioxide was only 33%, but additional label was detected in endogenous glutamate and aspartate. With washed mitochondria 30% oxidation of metabolized propionate occurred, and proportionately more citrate and malate accumulated. Recovery of (14)C in dicarboxylic acids, citrate, alpha-oxoglutarate, glutamate, aspartate and respiratory carbon dioxide was 91%. The specific activities of the products and the distribution of label in the carbon atoms of the dicarboxylic acids were consistent with the operation solely of the methylmalonate pathway together with limited oxidation of the succinate formed by the tricarboxylic acid cycle via pyruvate. In a final experiment with mitochondria the label consumed from [2-(14)C]propionate was entirely recovered in the intermediates of the tricarboxylic acid cycle, glutamate, aspartate, methylmalonate and respiratory carbon dioxide.
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Thermodynamics. Biophys Chem 1958. [DOI: 10.1016/b978-1-4832-2946-1.50008-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Swim H, Utter M. [24] Isotopic experimentation with intermediates of the tricarboxylic acid cycle. Methods Enzymol 1957. [DOI: 10.1016/0076-6879(57)04072-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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BRIL C. Enzymic micro-determination of succinate and fumarate in tissue homogenates. BIOCHIMICA ET BIOPHYSICA ACTA 1954; 15:258-62. [PMID: 13208691 DOI: 10.1016/0006-3002(54)90067-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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MITSUHASHI S, DAVIS BD. Aromatic biosynthesis. XII. Conversion of 5-dehydroquinic acid to 5-dehydroshikimic acid dy 5-dehydroquinase. BIOCHIMICA ET BIOPHYSICA ACTA 1954; 15:54-61. [PMID: 13198937 DOI: 10.1016/0006-3002(54)90093-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Humphrey GF, Mann T. Studies on the metabolism of semen. 5. Citric acid in semen. Biochem J 1949; 44:97-105. [PMID: 16748486 PMCID: PMC1274814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
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Krebs HA, Eggleston LV. Note on the manometric determination of succinic and alpha-ketoglutaric acids. Biochem J 1948; 43:17-8. [PMID: 16748360 PMCID: PMC1274626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- H A Krebs
- Medical Research Council Unit for Research in Cell Metabolism, Department of Biochemistry, The University, Sheffield
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Krebs HA, Eggleston LV. Metabolism of acetoacetate in animal tissues. 1. Biochem J 1945; 39:408-19. [PMID: 16747930 PMCID: PMC1258257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- H A Krebs
- Department of Biochemistry and the Medical Research Council Unit for Research in Cell Metabolism, University of Sheffield
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Evans E, Vennesland B, Slotin L. THE MECHANISM OF CARBON DIOXIDE FIXATION IN CELL-FREE EXTRACTS OF PIGEON LIVER. J Biol Chem 1943. [DOI: 10.1016/s0021-9258(18)72376-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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