Difference between revisions of "3-phosphoglycerate kinase"

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===Equilibrium constant===
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=== Equilibrium constant ===
 
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| 1974.16
 
| pH=7, T=25°C
 
| pH=7, T=25°C
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| Voet et al.<ref name="voet">Voet, D., Voet., J.G. and Pratt, C. W. (1999) Fundamentals of biochemistry, Wiley</ref> from Newshole et al. (1973) <ref name="newshole73">Newshole, E.A. and Stuart, C. (1973) Regulation in Metabolism, Wiley</ref>p 97:<br/>
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| Lehninger, (2008)<ref name="lehninger2008">David L. Nelson, Michael M. Cox (2008), Lehninger Principles of Biochemistry (5th edn), W. H. Freeman and Company</ref> p 553:<br/>
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<math>\Delta G' = 22.8\ kJ.mol^{-1}</math>, <math>Keq = exp(-\frac{\Delta G'}{RT}) = exp(\frac{-22800}{8.31*298.15}) \approx 0.10</math>
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<math>\Delta G' = -18.8\ kJ.mol^{-1}</math>, <math>Keq = exp(-\frac{\Delta G'}{RT}) = exp(\frac{18800}{8.31*298.15}) \approx 1974.16</math>
 
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| 0.067
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| 3333
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| pH=7, T=25°C
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| pH=6.9, T=298.15 K
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| Lehninger, (1975)<ref name="lehninger75">Lehninger, A.L. (1975) Biochemistry (2nd edn), Worth</ref> p 407:<br/>
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| From Krietsch et al. (1970) <ref name="krietsch70">Krietsch WZ and Bücher T. (1970) Eur J Biochem. 17(3):568-80. [[http://www.ncbi.nlm.nih.gov/pubmed?term=5493986 pmid: 5493986]]</ref>
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<math>\Delta G' = 23.8\ kJ.mol^{-1}</math>, <math>Keq = exp(-\frac{\Delta G'}{RT}) = exp(\frac{-23800}{8.31*298.15}) \approx 0.067</math>
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| 3571
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| pH=6.9, T=298.15 K
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| From Krietsch et al. (1970) <ref name="krietsch70"></ref>
 
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*Taking average from these values give <math>2960 \pm 861</math>
  
 
==References==
 
==References==
 
<references/>
 
<references/>

Revision as of 15:17, 24 June 2014

3-Phosphoglycerate kinase (PGK) is an enzyme that catalyzes the reversible transfer of a phosphate group from 1,3-bisphosphoglycerate (1,3-BPG) to ADP producing 3-phosphoglycerate (3-PG) and ATP. Like all kinases it is a transferase.

Chemical equation

1,3BPG + ADP \rightleftharpoons 3PG + ATP


Rate equation

Random Bi-Bi reversible Michaelis-Menten euation for non-interacting substrates are used. [1]

\frac{V_{mf}\frac{[1,3BPG][ADP]}{K_{1,3BPG} K_{ADP}} - V_{mr}\frac{[3PG][ATP]}{K_{3PG} K_{ATP}}}{1 + \frac{[1,3BPG]}{K_{1,3BPG}} + \frac{[ADP]}{K_{ADP}} + \frac{[1,3BPG][ADP]}{K_{1,3BPG} K_{ADP}} + \frac{[3PG][ATP]}{K_{3PG} K_{ATP}} + \frac{[3PG]}{K_{3PG}} + \frac{[ADP]}{K_{ADP}} }

Modified rate law to consider thermodynamic constraint

\frac{V_{mf}\frac{[1,3BPG][ADP]}{K_{1,3BPG} K_{ADP}} \left( 1 - \frac{[3PG][ATP]}{K_{eq} [1,3BPG][ADP]} \right)}{1 + \frac{[1,3BPG]}{K_{1,3BPG}} + \frac{[ADP]}{K_{ADP}} + \frac{[1,3BPG][ADP]}{K_{1,3BPG} K_{ADP}} + \frac{[3PG][ATP]}{K_{3PG} K_{ATP}} + \frac{[3PG]}{K_{3PG}} + \frac{[ADP]}{K_{ADP}} }



Parameter values

Parameter Value Units Organism Remarks
V_{mf} 8.7 [2] mM \times min^{-1} HeLa cell line
V_{mr} 2.5[1] mM \times min^{-1}
Km_{1,3BPG} 0.079[1] mM
Km_{3PG} 0.13[1] mM
Km_{ADP} 0.04[1] mM
Km_{ATP} 0.27[1] mM

Parameters with uncertainty

  • As the value of the K_{eq} does not depend on the organism, the mean and std. dev. of the distribution can be calculated from the various values reported in the literature. [3]
    Alternative: Same percent of error reported for V_{mf} can be considered for V_{mr} while the mean value as reported in [2] can be considered. In that case the value would be 2.5 \pm 1.15
Parameter Value Units Organism Remarks
V_{mf} 13 ± 6[2] mM \times min^{-1} Human
V_{mr} Sampled based on Haldane relation or Alternative value mM \times min^{-1}
Km_{1,3BPG} 0.0005 \pm 0.0002[4] mM
Km_{3PG}[4] 0.05 \pm 0.02 mM
Km_{ADP} 0.12 \pm 0.02[4] mM
Km_{ATP} 0.11 \pm 0.02[4] mM

Equilibrium constant

Equilibrium constant Conditions Source
1974.16 pH=7, T=25°C Lehninger, (2008)[5] p 553:

\Delta G' = -18.8\ kJ.mol^{-1}, Keq = exp(-\frac{\Delta G'}{RT}) = exp(\frac{18800}{8.31*298.15}) \approx 1974.16

3333 pH=6.9, T=298.15 K From Krietsch et al. (1970) [6]
3571 pH=6.9, T=298.15 K From Krietsch et al. (1970) [6]
  • Taking average from these values give 2960 \pm 861

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Marín-Hernández A, Gallardo-Pérez JC, Rodríguez-Enríquez S et al (2011) Modeling cancer glycolysis. Biochim Biophys Acta 1807:755–767 (doi)
  2. ↑ 2.0 2.1 2.2 Marín-Hernández A , Rodríguez-Enríquez S, Vital-González P A, et al. (2006). Determining and understanding the control of glycolysis in fast-growth tumor cells. Flux control by an over-expressed but strongly product-inhibited hexokinase. FEBS J., 273 , pp. 1975–1988(doi)
  3. ↑ Achcar, F., Kerkhoven, E. J., Bakker, B. M., Barrett, M. P., Breitling, R. (2012), Dynamic modelling under uncertainty: the case of Trypanosoma brucei energy metabolism, PLoS Comput. Biol. 8, e1002352.
  4. ↑ 4.0 4.1 4.2 4.3 Szabo, J.; Varga, A.; Flachner, B.; Konarev, P.V.; Svergun, D.I.; Zavodszky, P.; Vas, M. (2008), Role of side-chains in the operation of the main molecular hinge of 3-phosphoglycerate kinase, FEBS Lett. 582, 1335-1340
  5. ↑ David L. Nelson, Michael M. Cox (2008), Lehninger Principles of Biochemistry (5th edn), W. H. Freeman and Company
  6. ↑ 6.0 6.1 Krietsch WZ and Bücher T. (1970) Eur J Biochem. 17(3):568-80. [pmid: 5493986]
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