Difference between revisions of "Nucleosid diphosphate kinase"

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<center><math>\frac{ \frac{V_{max}}{K_m^{ATP}K_m^{UDP}}\left( [ATP][UDP] - \frac{[ADP][UTP]}{K_{eq}}  \right)  }  { \left( 1 + \frac{[ATP]}{K_{m}^{ATP}}  \right)\left( 1 + \frac{[UDP]}{K_{m}^{UDP}}  \right) + \left( 1 + \frac{[ADP]}{K_{m}^{ADP}}  \right)\left( 1 + \frac{[UTP]}{K_{m}^{UTP}}  \right) -1 }</math></center>
 
<center><math>\frac{ \frac{V_{max}}{K_m^{ATP}K_m^{UDP}}\left( [ATP][UDP] - \frac{[ADP][UTP]}{K_{eq}}  \right)  }  { \left( 1 + \frac{[ATP]}{K_{m}^{ATP}}  \right)\left( 1 + \frac{[UDP]}{K_{m}^{UDP}}  \right) + \left( 1 + \frac{[ADP]}{K_{m}^{ADP}}  \right)\left( 1 + \frac{[UTP]}{K_{m}^{UTP}}  \right) -1 }</math></center>
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 +
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==Parameter values==
 +
{|class="wikitable"
 +
! Parameter
 +
! Value
 +
! Units
 +
! Organism
 +
! Remarks
 +
|-
 +
|<math>V_{max}</math>
 +
|<math>200 \pm 21</math> <ref name = "villar_1960"> Villar-Palasi C & Larner J (1960). ''Levels of activity of the enzymes of the glycogen cycle in rat tissues''. Arch Biochem Biophys 86, 270–273.</ref>
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|<math>min^{-1}</math>
 +
|rowspan="6"|Recombinant, human muscle
 +
|rowspan="6"|
 +
|-
 +
|<math>K_{m}^{ATP}</math>
 +
|<math> 1.33 </math>
 +
|mM
 +
|-
 +
|<math>K_{m}^{ADP}</math>
 +
|<math>0.042</math>
 +
|mM
 +
|-
 +
|<math>K_{m}^{UTP}</math>
 +
|<math>16</math>
 +
|mM
 +
|-
 +
|<math>K_{m}^{UDP}</math>
 +
|<math>0.19</math>
 +
|mM
 +
|-
 +
|<math>K_{eq}</math>
 +
|<math>1</math>
 +
|Dimensionless
 +
|}
 +
 +
 +
 +
==Parameters with uncertainty==
 +
* The value of <math>V_{max}</math> is reported to be <math>9.6 %</math> of <math>V_{max, PGLM}</math>. The Std. Dev. for <math>V_{max, PGLM}</math> was considered to be <math>10.5%</math> of its mean value. Same error percentage is considered for <math>V_{max}</math>.
 +
 +
{|class="wikitable"
 +
! Parameter
 +
! Value
 +
! Units
 +
! Organism
 +
! Remarks
 +
|-
 +
|<math>V_{max}</math>
 +
|<math>200 \pm 21</math> <ref name = "villar_1960"> Villar-Palasi C & Larner J (1960). ''Levels of activity of the enzymes of the glycogen cycle in rat tissues''. Arch Biochem Biophys 86, 270–273.</ref>
 +
|<math>min^{-1}</math>
 +
|rowspan="6"|Recombinant, human muscle
 +
|rowspan="6"|
 +
|-
 +
|<math>K_{m}^{ATP}</math>
 +
|<math> 1.33 </math>
 +
|mM
 +
|-
 +
|<math>K_{m}^{ADP}</math>
 +
|<math>0.042</math>
 +
|mM
 +
|-
 +
|<math>K_{m}^{UTP}</math>
 +
|<math>16</math>
 +
|mM
 +
|-
 +
|<math>K_{m}^{UDP}</math>
 +
|<math>0.19</math>
 +
|mM
 +
|-
 +
|<math>K_{eq}</math>
 +
|<math>1</math>
 +
|Dimensionless
 +
|}
  
  
 
==References==
 
==References==
 
<references/>
 
<references/>

Revision as of 10:49, 13 May 2014

Nucleoside-diphosphate kinases are enzymes that catalyze the exchange of phosphate groups between different nucleotides. The overall effect of NDKs is to transfer a phosphate group from a nucleoside triphosphate to a nucleoside diphosphate. Starting with ATP and UDP, the activity of NDK produces ADP and UTP.

Chemical equation

ATP + UDP \leftrightarrow ADP + UTP

Rate equation

Random order Bi-Bi rate law is used from [1]

\frac{ \frac{V_{max}}{K_m^{ATP}K_m^{UDP}}\left( [ATP][UDP] - \frac{[ADP][UTP]}{K_{eq}} \right) } { \left( 1 + \frac{[ATP]}{K_{m}^{ATP}} \right)\left( 1 + \frac{[UDP]}{K_{m}^{UDP}} \right) + \left( 1 + \frac{[ADP]}{K_{m}^{ADP}} \right)\left( 1 + \frac{[UTP]}{K_{m}^{UTP}} \right) -1 }


Parameter values

Parameter Value Units Organism Remarks
V_{max} 200 \pm 21 [2] min^{-1} Recombinant, human muscle
K_{m}^{ATP} 1.33 mM
K_{m}^{ADP} 0.042 mM
K_{m}^{UTP} 16 mM
K_{m}^{UDP} 0.19 mM
K_{eq} 1 Dimensionless


Parameters with uncertainty

  • The value of V_{max} is reported to be 9.6 % of V_{max, PGLM}. The Std. Dev. for V_{max, PGLM} was considered to be 10.5% of its mean value. Same error percentage is considered for V_{max}.
Parameter Value Units Organism Remarks
V_{max} 200 \pm 21 [2] min^{-1} Recombinant, human muscle
K_{m}^{ATP} 1.33 mM
K_{m}^{ADP} 0.042 mM
K_{m}^{UTP} 16 mM
K_{m}^{UDP} 0.19 mM
K_{eq} 1 Dimensionless


References

  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
  2. ↑ 2.0 2.1 Villar-Palasi C & Larner J (1960). Levels of activity of the enzymes of the glycogen cycle in rat tissues. Arch Biochem Biophys 86, 270–273.
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