Difference between revisions of "Glyceraldehyde-3-phosphate dehydrogenase"

From ISMOC
Jump to: navigation, search
(→‎Parameters with uncertainty)
(→‎Parameters with uncertainty)
Line 80: Line 80:
 
|-
 
|-
 
|<math>Km_{1,3BPG}</math>
 
|<math>Km_{1,3BPG}</math>
−
|<math>0.013 \pm 0.0035</math><ref name="Hernandez2011"></ref>
+
|<math>0.013 \pm 0.0035</math>
 
|mM
 
|mM
 
|
 
|
 
|-
 
|-
 
|<math>Km_{NAD+}</math>
 
|<math>Km_{NAD+}</math>
−
|<math>0.019 \pm 0.007</math><ref name="Hernandez2011"></ref>
+
|<math>0.019 \pm 0.007</math>
 
|mM
 
|mM
 
|
 
|

Revision as of 11:31, 29 April 2014

The Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) enzyme serves two functions in glycolytic pathway. First the enzyme transfers a hydrogen (H-) from glyceraldehyde phosphate (Gly3P) to the oxidizing agent Nicotinamide Adenine Dinucleotide (NAD+) to form NADH. Next it adds a phosphate (P) from the cytosol to the oxidized Gly3P to form 1, 3-bisphosphoglycerate.

Chemical equation

NAD + Gly3P + Pi \rightleftharpoons 1,3BPG + NADH

Rate equation

Ordererd Ter-Bi reversible Michaelis-Menten equation for non-interacting substrates. [1]

v = \frac{ V_{mf}\frac{[NAD][Gly3P][Pi]}{K_{NAD}K_{Gly3P}K_{Pi}} - V_{mr} \frac{[1,3BPG][NADH]}{K_{1,3BPG}K_{NADH}} }{1 + \frac{[NAD]}{K_{NAD}} + \frac{[NAD][Gly3P]}{K_{NAD}K_{Gly3P}} + \frac{[NAD][Gly3P][Pi]}{K_{NAD}K_{Gly3P}K_{Pi}} + \frac{[1,3BPG][NADH]}{K_{1,3BPG}K_{NADH}} + +\frac{[NADH]}{K_{NADH}} }

Parameters

Parameter Value Units Organism Remarks
V_{mf} 0.58 [2] mM \times min^{-1} HeLa cell line
V_{mr} 0.72[2] mM \times min^{-1}
Km_{Gly3P} 0.19[1] mM
Km_{1,3BPG} 0.022[1] mM
Km_{NAD+} 0.09[1] mM
Km_{NADH} 0.01[1] mM
Km_{Pi} 29[1] mM

Parameters with uncertainty

  • Four values of Km_{NADH} have been collected from Lambeir et. al. (1991)[3] for different organisms. Km_{NADH} = 0.007 for Trypanosoma brucei, Km_{NADH} = 0.01 for Homo sapiens, Km_{NADH} = 0.012 for Geobacillus stearothermophilus and Km_{NADH} = 0.012 for Oryctolagus cuniculus. Calculating mean and std. dev. from these 4 values gives Km_{NADH} = 0.01025 \pm 0.002046
  • Three values collected under different conditions from human cell is reported for Km_{NAD+} in Ryzlak (1998) et. al. [4]. Those values are 0.01, 0.02, 0.027. The mean and Std. Dev. from these three values are Km_{NAD+} = 0.019 \pm 0.007
  • Three values for Km_{1,3BPG} have also been reported under different conditions from human cell in Ryzlak (1998) et. al. [4]. Those values are 0.01, 0.012, 0.018. The mean and Std. Dev. from these three values are Km_{1,3BPG} = 0.013 \pm 0.0035
Parameter Value Units Organism Remarks
V_{mf} 2 \pm 0.74 (5) [2] mM \times min^{-1} HeLa cell line
V_{mr} 2.5 \pm 0.8 (5)[2] mM \times min^{-1}
Km_{Gly3P} 0.19[1] mM
Km_{1,3BPG} 0.013 \pm 0.0035 mM
Km_{NAD+} 0.019 \pm 0.007 mM
Km_{NADH} 0.01025 \pm 0.002046 mM Multiple organism
Km_{Pi} 29[1] mM

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Marín-Hernández A, Gallardo-Pérez JC, Rodríguez-Enríquez S et al (2011) Modeling cancer glycolysis. Biochim Biophys Acta 1807:755–767 (doi)
  2. ↑ 2.0 2.1 2.2 2.3 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. ↑ Lambeir, A.M.; Loiseau, A.M.; Kuntz, D.A.; Vellieux, F.M.; Michels, P.A.M.; Opperdoes, F.R. (1991), The cytosolic and glycosomal glyceraldehyde-3-phosphate dehydrogenase from Trypanosoma brucei. Kinetic properties and comparison with homologous enzymes, Eur. J. Biochem. 198, 429-435
  4. ↑ 4.0 4.1 Ryzlak, M.T.; Pietruszko, R. (1998), Heterogeneity of glyceraldehyde-3-phosphate dehydrogenase from human brain, Biochim. Biophys. Acta 954, 309-324
Retrieved from ‘http://www.systemsbiology.ls.manchester.ac.uk/wiki/index.php?title=Glyceraldehyde-3-phosphate_dehydrogenase&oldid=1349’