Dehydrogenase

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	HeLa cell line
$K_{2}$	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. . 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. 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. We use the Range rule to calculate the mean and standard deviation from maximum and minimum value. For both $K_{1}$ the minimum and maximum value lies between 0.25 and 250000. So the mean for $K_{1}$ is 125000.125 and standard deviation would be 62500.0625 and for $K_{2}$ the minimum and maximum value lies between 0.001 and 1000. So the mean for $K_{2}$ is 500.0005 and standard deviation would be 250.00025.

Parameter	Value	Organism	Remarks
$K_{1}$	$125000.125 \pm 62500.0625$	HeLa cell line
$K_{2}$	$500.0005 \pm 250.00025$