Difference between revisions of "Hexose-6-phosphate isomerase"

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(→‎Parameters with uncertainty)
(→‎Parameters with uncertainty)
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==Parameters with uncertainty==
 
==Parameters with uncertainty==
 
[[Category:Uncertainty]]
 
[[Category:Uncertainty]]
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The uncertainty of <math>V_{mr}</math> and <math>Km_{Fru6P}</math> for HeLa cell line are calculated based on the same proportion of AS-30D cell reported in the paper Marín-Hernández ''et. al.'', ''Modeling cancer glycolysis'' <ref name="Hernandez2011"></ref>. The value of <math>Ki_{Ery4P}</math>, <math>Ki_{Fru1,6BP}</math> and <math>Ki_{6PG}</math> are adjusted in the interval of the corresponding inhibitor <ref name="Hernandez2011"></ref>. The standard deviations are also adjusted within this interval. The Xyl5P content is reported as <math>0.016\pm 0.0034</math> <ref name="Reitzer_1980">L.J. Reitzer, B.M. Wice, D. Kennell (1980), ''The pentose cycle'', J. Biol. Chem. 255 5616–5626</ref> and <math>Ki_{Ery4P}</math> is reported as 0.001. The ratio is determined as 0.0625. The standard deviation then comes as 0.0002125. Same principle is used for <math>Ki_{6PG}</math> where first the standard deviation for 6PG in HeLa cell line is calcualted based on the error ratio of AS-30D which is <math>0.39 \pm 0.144</math>. The standard deviation for <math>Ki_{6PG}</math> then comes as 0.005. There are two reported value for <math>Ki_{Fru1,6BP}</math>; 0.1<ref name ="Hernandez_2009">Marin-Hernandez, A., Gallardo-Perez, J. C., Ralph, S. J., Rodriguez-Enriquez, S. & Moreno-Sanchez, R. (2009), ''HIF-1α modulates energy metabolism in cancer cells by inducing over-expression of specific glycolytic isoforms.'' Mini-Rev. Med. Chem. 9, 1084–1101</ref>, 0.06<ref name="Hernandez2011"></ref>. The mean and standard deviation are calcualted from these two values.
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* The uncertainty of <math>V_{mr}</math> and <math>Km_{Fru6P}</math> for HeLa cell line are calculated based on the same proportion of uncertainty for AS-30D cell reported in the paper Marín-Hernández ''et. al.'', ''Modeling cancer glycolysis'' <ref name="Hernandez2011"></ref>.  
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*The value of <math>Ki_{Ery4P}</math>, <math>Ki_{Fru1,6BP}</math> and <math>Ki_{6PG}</math> are adjusted in the interval of the corresponding inhibitor <ref name="Hernandez2011"></ref>. The standard deviations are also adjusted within this interval. The Xyl5P content is reported as <math>0.016\pm 0.0034</math> <ref name="Reitzer_1980">L.J. Reitzer, B.M. Wice, D. Kennell (1980), ''The pentose cycle'', J. Biol. Chem. 255 5616–5626</ref> and <math>Ki_{Ery4P}</math> is reported as 0.001. The ratio is determined as 0.0625. The standard deviation then comes as 0.0002125. Same principle is used for <math>Ki_{6PG}</math> where first the standard deviation for 6PG in HeLa cell line is calcualted based on the error ratio of AS-30D which is <math>0.39 \pm 0.144</math>. The standard deviation for <math>Ki_{6PG}</math> then comes as 0.005. There are two reported value for <math>Ki_{Fru1,6BP}</math>; 0.1<ref name ="Hernandez_2009">Marin-Hernandez, A., Gallardo-Perez, J. C., Ralph, S. J., Rodriguez-Enriquez, S. & Moreno-Sanchez, R. (2009), ''HIF-1α modulates energy metabolism in cancer cells by inducing over-expression of specific glycolytic isoforms.'' Mini-Rev. Med. Chem. 9, 1084–1101</ref>, 0.06<ref name="Hernandez2011"></ref>. The mean and standard deviation are calcualted from these two values.
  
 
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Revision as of 09:13, 24 April 2014

The enzyme Hexose-6-phosphate isomerase converts Glucose 6-phosphate (Glc6P) into its isomer Fructose 6-phosphate (Fru6P). Isomers have the same molecular formula, but the atoms of each molecule are arranged differently.

Chemical reaction

Glc6P \rightleftharpoons Fru6P

Rate equation

Reversible competitive inhibition with Ery4P, 6PG and FBP. [1]

Failed to parse (Cannot store math image on filesystem.): \frac{V_{mf}\frac{[Glc6P]}{Km_{Glc6P}} - V_{mr} \frac{[Fru6P]}{Km_{Fru6P}} }{ 1 + \frac{[Glc6P]}{Km_{Glc6P}} + \frac{[Fru6P]}{Km_{Fru6P}} + \frac{[ERY4P]}{Ki_{ERY4P}} + \frac{[6PG]}{Ki_{6PG}} + \frac{[Fru1,6BP]}{Ki_{Fru1,6BP}} }

Parameter values

Parameter Value Units Organism Remarks
V_{mf} 0.4 [1] mM \times min^{-1} HeLa cell line 3 cell assays
V_{mr} 0.9[1] mM \times min^{-1} 1 cell assay
Km_{Glc6P} 0.4 \pm 0.03 mM[1] mM 3 cell assays
Km_{Fru6P} 0.05[1] mM 2 cell assays
Ki_{ERY4P} 0.001[1] mM Adjusted in the interval based on activity[1]
Ki_{Fru1,6BP} 0.06[1] mM Adjusted in the interval based on activity[1]
Ki_{6PG} 0.015[1] mM Adjusted in the interval based on activity[1]

Parameters with uncertainty

  • The uncertainty of V_{mr} and Km_{Fru6P} for HeLa cell line are calculated based on the same proportion of uncertainty for AS-30D cell reported in the paper Marín-Hernández et. al., Modeling cancer glycolysis [1].
  • The value of Ki_{Ery4P}, Ki_{Fru1,6BP} and Ki_{6PG} are adjusted in the interval of the corresponding inhibitor [1]. The standard deviations are also adjusted within this interval. The Xyl5P content is reported as Failed to parse (Cannot store math image on filesystem.): 0.016\pm 0.0034 [2] and Ki_{Ery4P} is reported as 0.001. The ratio is determined as 0.0625. The standard deviation then comes as 0.0002125. Same principle is used for Ki_{6PG} where first the standard deviation for 6PG in HeLa cell line is calcualted based on the error ratio of AS-30D which is Failed to parse (Cannot store math image on filesystem.): 0.39 \pm 0.144 . The standard deviation for Ki_{6PG} then comes as 0.005. There are two reported value for Ki_{Fru1,6BP}; 0.1[3], 0.06[1]. The mean and standard deviation are calcualted from these two values.
Parameter Value Units
V_{mf} 1.2 \pm 0.2 [1] mM \times min^{-1}
V_{mr} Failed to parse (Cannot store math image on filesystem.): 2.8 \pm 0.9058 [1] mM \times min^{-1}
Km_{Glc6P} 0.4 \pm 0.03 mM[1] mM
Km_{Fru6P} 0.05 \pm 0.0214 [1] mM
Ki_{ERY4P} Failed to parse (Cannot store math image on filesystem.): 0.001\pm 0.0002125 [1] mM
Ki_{Fru1,6BP} 0.08 \pm 0.02 mM
Ki_{6PG} Failed to parse (Cannot store math image on filesystem.): 0.015 \pm 0.005 [1] mM

Refences

  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 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 Cite error: Invalid <ref> tag; name "Hernandez2011" defined multiple times with different content Cite error: Invalid <ref> tag; name "Hernandez2011" defined multiple times with different content Cite error: Invalid <ref> tag; name "Hernandez2011" defined multiple times with different content
  2. ↑ L.J. Reitzer, B.M. Wice, D. Kennell (1980), The pentose cycle, J. Biol. Chem. 255 5616–5626
  3. ↑ Marin-Hernandez, A., Gallardo-Perez, J. C., Ralph, S. J., Rodriguez-Enriquez, S. & Moreno-Sanchez, R. (2009), HIF-1α modulates energy metabolism in cancer cells by inducing over-expression of specific glycolytic isoforms. Mini-Rev. Med. Chem. 9, 1084–1101
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