Thermodynamics of hexokinase catalyzed reactions. II. Measurement and calculation of enthalpies of reaction as a function of magnesium ion concentration.


Journal Article

Enthalpies of phosphorylation of glucose by adenosine 5'-triphosphate have been measured as a function of concentrations of magnesium chloride in TRIS/TRIS-HCl buffer in the pH range 8.64 to 8.98. These measurements are compared with the results of calculations of these enthalpies that use a coupled equilibrium formalism with equilibrium data and enthalpy values selected from the literature. The experimental results span the range of magnesium ion concentrations 1 X 10(-6) to 0.3 mol alpha-1 and show a total variation in the enthalpy of reaction of almost 10 kJ mol-1, with the most exothermic reaction occurring at a magnesium ion concentration of 6.0 X 10(-4) mol alpha-1. The calculated enthalpies of reaction, except for the magnesium ion concentration range 4 X 10(-6) to 5 X 10(-4) mol alpha-1, are, within estimated uncertainty intervals (0.8 to 10.2 kJ mol-1), in agreement with the measured values.

Full Text

Cited Authors

  • Goldberg, RN

Published Date

  • May 1, 1976

Published In

Volume / Issue

  • 4 / 3

Start / End Page

  • 215 - 221

PubMed ID

  • 7326

Pubmed Central ID

  • 7326

Electronic International Standard Serial Number (EISSN)

  • 1873-4200

International Standard Serial Number (ISSN)

  • 1873-4200

Digital Object Identifier (DOI)

  • 10.1016/0301-4622(76)80067-1


  • eng