Difference between revisions of "Triosephosphate isomerase"
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==Parameters with uncertainty== | ==Parameters with uncertainty== | ||
− | * The activity is measured in Activity in the reverse reaction in Hernandez (2006) ''et. al.'' <math>V_{mf}</math> is sampled based on Haldane equation <math>K_{eq} = \frac{V_{forward}*K_{product}}{V_{reverse}*K_{substrate}}</math> using the value <math>K_{eq} = | + | * The activity is measured in Activity in the reverse reaction in Hernandez (2006) ''et. al.'' <math>V_{mf}</math> is sampled based on Haldane equation <math>K_{eq} = \frac{V_{forward}*K_{product}}{V_{reverse}*K_{substrate}}</math> using the value <math>K_{eq} = 0.047</math>, <math>Km_{Gly3P}</math> and <math>Km_{DHAP}</math>. <br> |
− | '''Alternative-1''' the reported fixed point value can be considered with the standard deviation calculated based on the same ratio of <math>V_{mf}</math> which is <math>\approx 31%</math>. This gives the value <math>V_{mf}= | + | '''Alternative-1''' the reported fixed point value can be considered with the standard deviation calculated based on the same ratio of <math>V_{mf}</math> which is <math>\approx 31%</math>. This gives the value <math>V_{mf}=6.19 \pm 1.91 </math><math>U\cdot(\text{mg protein})^{-1}</math><br> |
'''Alternative-2''' Calculating <math>V_{mf}</math> from <math>V_{mr}</math> based on Haldane equation which gives the value of 2.911 and with the same percent of erro Std. Dev. is 0.90. | '''Alternative-2''' Calculating <math>V_{mf}</math> from <math>V_{mr}</math> based on Haldane equation which gives the value of 2.911 and with the same percent of erro Std. Dev. is 0.90. | ||
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|- | |- | ||
|<math>V_{mf}</math> | |<math>V_{mf}</math> | ||
− | | Sampled based on the Haldane equation.<br> '''Alternative:''' <math> | + | | Sampled based on the Haldane equation.<br> '''Alternative:''' <math>6.19 \pm 1.91</math> or <math>2.911 \pm 0.90</math> conversion gives <math>402 \pm 124.62</math> |
− | |<math> mM \times min^{-1} </math> | + | |<math>U\cdot(\text{mg protein})^{-1}</math> <br> <math> mM \times min^{-1} </math> |
| | | | ||
|rowspan="5"| | |rowspan="5"| | ||
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|<math>K_{eq}(reverse) = 20.9, and so K_{eq}(forward) = \frac{1}{20.9} = 0.047 </math> | |<math>K_{eq}(reverse) = 20.9, and so K_{eq}(forward) = \frac{1}{20.9} = 0.047 </math> | ||
|} | |} | ||
+ | |||
+ | ===Equilibrium constant=== | ||
+ | {| class="wikitable" | ||
+ | ! Equilibrium constant | ||
+ | ! Conditions | ||
+ | ! Source | ||
+ | |- | ||
+ | | 0.045 | ||
+ | | pH=8, T=25°C | ||
+ | | Bergmeyer ''Methods of enzymatic analysis'' page 515<ref name="bermeyer74">Bergmeyer H.U. (1974) ''Methods of enzymatic analysis'', Publisher: Verlag Chemie (vol 1)</ref> | ||
+ | |- | ||
+ | | 0.041 | ||
+ | | pH=7, T=25°C | ||
+ | | Voet et al.<ref name="voet">Voet, D., Voet., J.G. and Pratt, C. W. (1999) Fundamentals of biochemistry, Wiley</ref> from Newshole et al. (1973) <ref name="newshole73">Newshole, E.A. and Stuart, C. (1973) Regulation in Metabolism, Wiley</ref>p 97:<br/> | ||
+ | <math>\Delta G' = 7.9\ kJ.mol^{-1}</math>, <math>Keq = exp(-\frac{\Delta G'}{RT}) = exp(\frac{-7900}{8.31*298.15}) \approx 0.041</math> | ||
+ | |- | ||
+ | | 0.048 | ||
+ | | pH=7, T=25°C | ||
+ | | Lehninger, (1975)<ref name="lehninger75">Lehninger, A.L. (1975) Biochemistry (2nd edn), Worth</ref> p 408:<br/> | ||
+ | <math>\Delta G' = 7.5\ kJ.mol^{-1}</math>, <math>Keq = exp(-\frac{\Delta G'}{RT}) = exp(\frac{-7500}{8.31*298.15}) \approx 0.048</math> | ||
+ | |- | ||
+ | | 0.0475 | ||
+ | | pH=7, T=25°C | ||
+ | | Lehninger, (1975)<ref name="lehninger75">Lehninger, A.L. (1975) Biochemistry (2nd edn), Worth</ref> p 396. | ||
+ | |} | ||
+ | |||
+ | *Taking average of all those values give <math>0.0457 \pm 0.002863</math> | ||
==References== | ==References== | ||
<references/> | <references/> |
Latest revision as of 14:23, 28 October 2014
This enzyme rapidly inter-converts the molecules Dihydroxyacetone phosphate (DHAP) and Glyceraldehyde 3-phosphate (Gly3P). Gly3P is removed as soon as it is formed to be used in the next step of glycolysis.
Contents
Chemical equation
Rate equation
Reversible Michaelis-Menten is used [1]
Modified rate law considering thermodynamic constant is
Paramters
Parameter | Value | Units | Organism | Remarks |
---|---|---|---|---|
5 [1] | Hela cell line | |||
42[2] | ||||
0.51[1] | mM | |||
1.6[1] | mM |
Parameters with uncertainty
- The activity is measured in Activity in the reverse reaction in Hernandez (2006) et. al. is sampled based on Haldane equation using the value , and .
Alternative-1 the reported fixed point value can be considered with the standard deviation calculated based on the same ratio of which is . This gives the value
Alternative-2 Calculating from based on Haldane equation which gives the value of 2.911 and with the same percent of erro Std. Dev. is 0.90.
Parameter | Value | Units | Organism | Remarks |
---|---|---|---|---|
Sampled based on the Haldane equation. Alternative: or conversion gives |
|
|||
[2] | ||||
[3] | mM | Human liver | ||
[3] | mM | Human liver | ||
[3] | mM |
Equilibrium constant
Equilibrium constant | Conditions | Source |
---|---|---|
0.045 | pH=8, T=25°C | Bergmeyer Methods of enzymatic analysis page 515[4] |
0.041 | pH=7, T=25°C | Voet et al.[5] from Newshole et al. (1973) [6]p 97: , |
0.048 | pH=7, T=25°C | Lehninger, (1975)[7] p 408: , |
0.0475 | pH=7, T=25°C | Lehninger, (1975)[7] p 396. |
- Taking average of all those values give
References
- ↑ 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) Cite error: Invalid
<ref>
tag; name "Hernandez2011" defined multiple times with different content - ↑ 2.0 2.1 Marín-Hernández A , Rodríguez-Enríquez S, Vital-González P A, et al. (2006). Determining and understanding the control of glycolysis in fast-growth tumor cells. Flux control by an over-expressed but strongly product-inhibited hexokinase. FEBS J., 273 , pp. 1975–1988(doi)
- ↑ 3.0 3.1 3.2 Snyder, R.; Lee, E.W. (1975), Triosephosphate isomerase from human and horse liver,Methods Enzymol. 41B, 430-434
- ↑ Bergmeyer H.U. (1974) Methods of enzymatic analysis, Publisher: Verlag Chemie (vol 1)
- ↑ Voet, D., Voet., J.G. and Pratt, C. W. (1999) Fundamentals of biochemistry, Wiley
- ↑ Newshole, E.A. and Stuart, C. (1973) Regulation in Metabolism, Wiley
- ↑ 7.0 7.1 Lehninger, A.L. (1975) Biochemistry (2nd edn), Worth