3-phosphoglycerate kinase

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

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}} }

Parameter	Value	Units	Organism
$V_{mf}$	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

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
$V_{mf}$	$13 ± 6$ ^[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	Conditions	Source
0.10	pH=7, T=25°C	Voet et al.^[5] from Newshole et al. (1973) ^[6]p 97: $\Delta G' = 22.8\ kJ.mol^{-1}$ , $Keq = exp(-\frac{\Delta G'}{RT}) = exp(\frac{-22800}{8.31*298.15}) \approx 0.10$
0.067	pH=7, T=25°C	Lehninger, (1975)^[7] p 407: $\Delta G' = 23.8\ kJ.mol^{-1}$ , $Keq = exp(-\frac{\Delta G'}{RT}) = exp(\frac{-23800}{8.31*298.15}) \approx 0.067$

↑ ^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)
↑ ^2.0 ^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)
↑ 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.
↑ ^4.0 ^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
↑ Voet, D., Voet., J.G. and Pratt, C. W. (1999) Fundamentals of biochemistry, Wiley
↑ Newshole, E.A. and Stuart, C. (1973) Regulation in Metabolism, Wiley
↑ Lehninger, A.L. (1975) Biochemistry (2nd edn), Worth