UDPG-pyrophosphorylase
This enzyme converts UTP and G1P to UDP-glucose (UDPG) and pyrophosphate (PPi)
Contents
Chemical equation
![UTP + Glc1P \rightarrow UDPG + PPi](/wiki/images/math/1/6/4/164aa6f2c28a35106b6863963256107a.png)
Rate equation
Reversible Bi substrate Michaelis-Menten equation with random binding order is used [1]
![\frac{ \frac{V_{max}}{K_{UTP}K_{Glc1P}} \left( [UTP][Glc1P] - \frac{[UDPG][PPi]}{K_{eq}} \right) }{ \left( 1 + \frac{[UTP]}{K_{UTP}} + \frac{[PPi]}{K_{PPi}} \right) \left( 1 + \frac{[UDPG]}{K_{UDPG}} + \frac{[Glc1P]}{K_{Glc1P}} \right) }](/wiki/images/math/5/c/b/5cb04d31df5c22ab51ad23a54e27d997.png)
Parameter values
Parameter | Value | Units | Organism | Remarks |
---|---|---|---|---|
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200 [2] | ![]() |
Recombinant, human muscle | |
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0.4 [3] | mM | ||
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0.92 [3] | mM | ||
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mM | ||
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mM | ||
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Dimensionless |
Parameters with uncertainty
- The value of
is reported to be
of
. The Std. Dev. for
was considered to be
of its mean value. Same error percentage is considered for
.
Parameter | Value | Units | Organism | Remarks |
---|---|---|---|---|
![]() |
![]() |
![]() |
Recombinant, human muscle | |
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mM | ||
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mM | ||
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mM | ||
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mM | ||
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Dimensionless |
Equilibrium constant
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 [[1]] from Atkinson et al. (1958) [5]
Therefore, |
References
- ↑ Palm, D.C. (2013). The regulatory design of glycogen metabolism in mammalian skeletal muscle (Ph.D.). University of Stellenbosch
- ↑ 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.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Duggleby RG, Chao YC, Huang JG, Peng HL & Chang HY (1996). Sequence differences between human muscle and liver cDNAs for UDPglucose pyrophosphorylase and kinetic properties of the recombinant enzymes expressed in Escherichia coli. Eur J Biochem 235, 173–179.
- ↑ Bergamini C, Signorini M, Ferrari C & Dallocchio F (1983), Non-Michaelian kinetics of rabbit muscle uridine diphosphoglucose pyrophosphorylase, Arch Biochem Biophys 227, 397–405
- ↑ Turner, D.H.; Turner, J.F.; Biochem. J.; 69, 448 (1958)