Difference between revisions of "6-phosphogluconate dehydrogenase"

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== Rate equation ==
 
== Rate equation ==
 
The basic reactio mechanism can be modelled with an ordered Bi-ter equation <ref name="Toews1976"> Toews, Myron L., M. I. Kanji, and W. R. Carper. "6-Phosphogluconate dehydrogenase. Purification and kinetics." Journal of Biological Chemistry 251.22 (1976): 7127-7131. ([http://www.jbc.org/content/251/22/7127.short])  </ref>
 
The basic reactio mechanism can be modelled with an ordered Bi-ter equation <ref name="Toews1976"> Toews, Myron L., M. I. Kanji, and W. R. Carper. "6-Phosphogluconate dehydrogenase. Purification and kinetics." Journal of Biological Chemistry 251.22 (1976): 7127-7131. ([http://www.jbc.org/content/251/22/7127.short])  </ref>
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<math>v=\frac{V_{max}*[NADP^+]*[6-PGA]}{k_{iNADP}*k_{6-PGA}+k_{6-PGA}*[NADP^+]+k_{NADP^+}*[6-PGA]+[NADP^+]*[6-PGA]}</math>
 
<math>v=\frac{V_{max}*[NADP^+]*[6-PGA]}{k_{iNADP}*k_{6-PGA}+k_{6-PGA}*[NADP^+]+k_{NADP^+}*[6-PGA]+[NADP^+]*[6-PGA]}</math>
  

Revision as of 15:33, 23 June 2014

6-phosphogluconate dehydrogenase is the third enzyme of the Pentose Phosphate pathway. It catalyses the oxidative decarboxylation of 6-phosphogluconate using NADP+. The product of this reaction is ribulose 5-P, CO2 and NADPH. This is the second step of the pentose phosphate pathway producing NADPH and the last step of the oxidative phase.

Chemical reaction

6-PGA + NADP^+ \rightleftharpoons Rbu-5-P + NADPH + CO_{2}

Rate equation

The basic reactio mechanism can be modelled with an ordered Bi-ter equation [1]


v=\frac{V_{max}*[NADP^+]*[6-PGA]}{k_{iNADP}*k_{6-PGA}+k_{6-PGA}*[NADP^+]+k_{NADP^+}*[6-PGA]+[NADP^+]*[6-PGA]}

Parameters values

Name Value Units Organism Remarks
Km 6-PGA 0.0292[1] mM Pig liver
0.051±0.021[2] mM Recombinant human protein
0.063±0.004[2] mM Recombinant human protein
0.06±0.005[2] mM Recombinant human protein
0.016±0.0008[2] mM Human liver
0.023±0.0001[2] mM Human erythrocyte
0.041[2] mM Human Brain
Km NADP 0.0135[1] mM Pig liver
0.018±0.0008[2] mM Recombinant human protein
0.025 ± 0.001[2] mM Recombinant human protein
0.022 ± 0.0004[2] mM Recombinant human protein
0.0037[2] mM Human Brain
Vmax 0.00493*10-3[1] mM/min Pig liver
Kcat 73 ± 19[2] Recombinant human protein
57 ± 2[2] Recombinant human protein
44 ± 4[2] Recombinant human protein
21 ± 0.07[2] Human liver
21.3 ± 0.01[2] Human erythrocyte

References

  1. 1.0 1.1 1.2 1.3 Toews, Myron L., M. I. Kanji, and W. R. Carper. "6-Phosphogluconate dehydrogenase. Purification and kinetics." Journal of Biological Chemistry 251.22 (1976): 7127-7131. ([1])
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 Barden Chan, Vikas P. Sukhatme, One-step purification of soluble recombinant human 6-phosphogluconate dehydrogenase from Escherichia coli, Protein Expression and Purification, Volume 92, Issue 1, November 2013, Pages 62-66, ISSN 1046-5928 ([2])