Difference between revisions of "Pyrophosphate phosphohydrolase"

Latest revision as of 13:18, 1 July 2014

Pyrophosphate phosphohydrolase that catalyze the reaction that converts Pyrophosphate into two molecules of Phosphate.

PPi \rightarrow 2 Pi

Simple Michaelis-Menten rate law is used for this reaction ^[1]

\frac{V_{max[PP]}}{[PP] + K_{m}^{PP}}

A mean body weight is defined as 75Kg in Konig et. al ^[1]. The $V_{max}$ is calculated by multiplying the reported value with body weight.

Parameter	Value	Units	Organism	Remarks
$V_{max}$	$0.36$	$mM/min^{-1}$	Human Liver
$K_{m}^{PPi}$	$0.96$	mM	Human cancer

The minimum and maximum value for $K_{m}^{PPi}$ has been reported to be 0.25 and 1.67. Calculating the mean and Std. Dev. using the range formula gives a value of $0.96 \pm 0.35$ for this parameter.
No Std. Dev. for $V_{max}$ have been reported. Therefore the relative percent standard error is calculated for all the $V_{max}$ which is $\approx 71%$ . Taking this value the Std. Dev. for $V_{max}$ is 0.2556.

Parameter	Value	Units	Organism	Remarks
$V_{max}$	$0.36 \pm 0.2556$	$mM/min^{-1}$	Human Liver
$K_{m}^{PPi}$	$0.96 \pm 0.35$	mM	Rat liver

↑ ^1.0 ^1.1 M. König, S. Bulik, H.G. Holzhütter (2012), Quantifying the contribution of the liver to glucose homeostasis: a detailed kinetic model of human hepatic glucose metabolism, PLoS Comput. Biol., 8 (6), p. e1002577

@@ Line 36: / Line 36: @@
 ==Parameters with uncertainty==
 * The minimum and maximum value for <math>K_{m}^{PPi}</math> has been reported to be 0.25 and 1.67. Calculating the mean and Std. Dev. using the '''range formula''' gives a value of <math>0.96 \pm 0.35</math> for this parameter.
+* No Std. Dev. for <math>V_{max}</math> have been reported. Therefore the relative percent standard error is calculated for all the <math>V_{max}</math> which is <math>\approx 71%</math>. Taking this value the Std. Dev. for <math>V_{max}</math> is 0.2556.
 {|class="wikitable"
@@ Line 45: / Line 46: @@
 |-
 |<math>V_{max}</math>
-|<math>0.36</math>
+|<math>0.36 \pm 0.2556</math>
 |<math>mM/min^{-1}</math>
 |Human Liver