Difference between revisions of "Adenylate kinase"

Revision as of 16:34, 28 May 2014

Adenylate kinase is a phosphotransferase enzyme that catalyzes the interconversion of adenine nucleotides.

ATP + AMP \rightleftharpoons 2ADP

Reversible mass action rate law is used

K_{1}[ATP][AMP] - K_{2}[ADP]^2

Parameter	Value	Organism	Remarks
$K_{1}$	1 ^[1]	HeLa cell line
$K_{2}$	2.26 ^[1]	HeLa cell line

Parameter	Value
Failed to parse (Cannot store math image on filesystem.): K_1=1 , $K_2=2.26$	The Adenylate kinase was modeled using mass action kinetics with parameters $K_1$ and $K_2$ consistent with the equilibrium constant of the reaction. The equilibrium constant (Keq=2.26) is from Bergmeyer H.U. (1974) page 486^[2]: $Keq(ATP+AMP \rightarrow 2*ADP, pH=7.4, T=25^oC)=2.26$ In Mass action rate law the relationship is $\frac{K_2}{K_1} = K_{eq}$ . Considering $K_{eq} = 2.26$ we have $K_2=2.26$ and $K_1 = 1$ to be consistent with the equation. The value of $K_1$ and $K_2$ would be varied based on the uncertainty on $K_{eq}$ value mentioned in the following table. The percentage of error in Keq is $\approx 4$ . With similar percent of error the value for $K_1 = 1 \pm 0.04$ and $K_2 = 2.26 \pm 0.09044$

Equilibrium constant	Conditions	Source
0.48+/-0.015 (mean+/-SEM; n=7)	pH=7, T=25°C, 10mM Mg2+	NIST database "Thermodynamics of Enzyme-Catalyzed Reactions" entry [61ATK/BUR_640] from Atkinson et al. (1961) ^[3] Table 2 Therefore, Keq(forward) = 0.48 +/-0.015 (n=7; mean+/-SEM calculated from individual measurements).

↑ ^1.0 ^1.1 Marín-Hernández A, Gallardo-Pérez JC, Rodríguez-Enríquez S et al (2011) Modeling cancer glycolysis. Biochim Biophys Acta 1807:755–767 (doi)
↑ Bergmeyer H.U. (1974) Methods of enzymatic analysis, Publisher: Verlag Chemie (vol 1)
↑ Atkinson, M. R., Burton, R. M. and Morton, R. K. (1961) Biochem J. 78(4):813–820. (pmid: 13684980)

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 | The Adenylate kinase was modeled using mass action kinetics with parameters <math>K_1</math> and <math>K_2</math> consistent with the equilibrium constant of the reaction. The equilibrium constant (Keq=2.26) is from Bergmeyer H.U. (1974) page 486<ref name="bergmeyer74">Bergmeyer H.U. (1974) ''Methods of enzymatic analysis'', Publisher: Verlag Chemie (vol 1)</ref>:
 <math>Keq(ATP+AMP  \rightarrow 2*ADP, pH=7.4, T=25^oC)=2.26</math><br/>
-In Mass action rate law the relationship is <math>\frac{K_2}{K_1} = K_{eq}</math>. Considering <math>K_{eq} = 2.26</math> we have <math>K_2=2.26</math> and <math>K_1 = 1</math> to be consistent with the equation. The value of <math>K_1</math> and <math>K_2</math> would be varied based on the uncertainty on <math>K_{eq}</math> value mentioned in the following table.
+In Mass action rate law the relationship is <math>\frac{K_2}{K_1} = K_{eq}</math>. Considering <math>K_{eq} = 2.26</math> we have <math>K_2=2.26</math> and <math>K_1 = 1</math> to be consistent with the equation. The value of <math>K_1</math> and <math>K_2</math> would be varied based on the uncertainty on <math>K_{eq}</math> value mentioned in the following table. The percentage of error in Keq is <math>\approx 4</math>. With similar percent of error the value for <math>K_1 = 1 \pm 0.04</math> and <math>K_2 = 2.26 \pm 0.09044</math>
 |}