Dehydrogenase

From ISMOC
Revision as of 11:07, 15 May 2014 by Galib36 (talk | contribs) (Parameters with uncertainty)
Jump to: navigation, search


A dehydrogenase is an enzyme that oxidizes a substrate by a reduction reaction that transfers one or more hydrides (H) to an electron acceptor, usually Nicotinamide adenine dinucleotide NAD+/NADP.

Chemical reaction

 NADH \rightleftharpoons NAD

Rate equation

Reversible mass action rate law is used

K_{1}[NADH] - K_{2}[NAD]

Parameters

Parameter Value Organism Remarks
K_{1} 250 [1] HeLa cell line
K_{2} 1[1]


Parameters with uncertainty

  • This is a pseudo-reaction, modelled using mass action kinetics (i.e., as non-saturable, non-enzymatic reactions) to maintain maximal compatibility with Pyridine Nucleotides balances. The parameter values were adjusted through model simulations and the values chosen were those that best predicted NAD+ concentration (determined experimentally) in Hernandez et. al. [1]. No information is available about the uncertainty of these parameters. As these parameters are strictly positive, they are sampled using a log-normal distribution as are and values. The means are set to the value using fitted by Hernandez et al. [1] for the fixed-parameter model. The sampling of the parameters are made to fall within [0.001\times mean \quad 1000 \times mean  ] to allow a large exploration of the parameter space.


Parameter Value Organism Remarks
K_{1} Sampled between 0.25 and 250000 HeLa cell line
K_{2} Sampled between 0.001 and 1000

References

  1. 1.0 1.1 1.2 1.3 Marín-Hernández A, Gallardo-Pérez JC, Rodríguez-Enríquez S et al (2011) Modeling cancer glycolysis. Biochim Biophys Acta 1807:755–767 (doi)