Hexokinase
The enzyme hexokinase phosphorylates (adds a phosphate group to) glucose in the cell's cytoplasm. In the process, a phosphate group from Adenosine triphosphate (ATP) is transferred to glucose producing glucose 6-phosphate (Glc6P).
Contents
Chemical equation
![Glucose_{in} + ATP \rightleftharpoons Glc6P + ADP](/wiki/images/math/5/1/c/51c1f51b54e383ab569baf582d5d2aab.png)
Rate equation
Without inhibition
Random Bi-Bi Michaelis Menten is used.[1]
![v = \frac{\frac{V_{mf}}{Km_{Glucose_{in}}K_{ATP}}\Big( [Glucose_{in}][ATP] - \frac{[Glc6P][ADP]}{K_{eq}} \Big)}{1 + \frac{[Glucose_{in}]}{Km_{Glucose_{in}}} + \frac{[ATP]}{K_{ATP}} + \frac{[Glucose_{in}][ATP]}{Km_{Glucose_{in}}K_{ATP}} + \frac{[Glc6P]}{K_{Glc6P}} + \frac{[ADP]}{K_{ADP}} +\frac{[Glc6P][ADP]}{K_{Glc6P}K_{ADP}} + \frac{[Glucose_{in}][ADP]}{K_{Glucose_{in}}K_{ADP}} +\frac{[Glc6P][ATP]}{K_{Glc6P}K_{ATP}} }](/wiki/images/math/d/2/d/d2d1c3d1115eef8cdf23e7eb98f65b04.png)
With allosteric inhibition
![\frac{V_{mf}* \frac{[Glucose]*[ATP]}{Km_{Glucose}*Km_{ATP}} }{ \left(1 + \frac{[Glc6P]}{Ki_{Glc6P}} \right)* \left( 1 + \frac{[Glucose]}{Km_{Glucose}} \right) + \frac{[ATP]}{Km_{ATP}} + \frac{[Glucose]*[ATP]}{Km_{Glucose}*Km_{ATP}} }](/wiki/images/math/c/2/6/c26962b0cefb2c26a75d64c2de18328e.png)
Parameters
Without inhibition
Parameter | Value | Organism | Remarks |
---|---|---|---|
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0.06 [2] | HeLa cell line | |
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651[3] | ||
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0.1[1] | ||
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1.1[1] | ||
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3.5[1] |
With inhibition
Parameter | Value | Organism | Remarks |
---|---|---|---|
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0.06 [2] | HeLa cell line | |
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0.1[1] | ||
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1.1[1] | ||
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Alternative parameter values
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Marín-Hernández A, Gallardo-Pérez JC, Rodríguez-Enríquez S et al (2011) Modeling cancer glycolysis. Biochim Biophys Acta 1807:755–767 (doi)
- ↑ 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) Cite error: Invalid
<ref>
tag; name "Hernandez_2006" defined multiple times with different content - ↑ Arbitrary value
- ↑ Wilson J E (2003). Isozymes of mammalian hexokinase: structure, subcellular localization and metabolic function. Journal of Experimental Biology, 206, pp. 2049–2057 (doi)