Thermodynamic data on enzyme-catalyzed reactions play an important role in the prediction of the extent of reaction and the position of equilibrium for any process in which these reactions occur. Applications include biomanufacturing, metabolic engineering and metabolic control analysis, process optimization, pharmaceuticals, foods, bulk commodity chemicals and biofuels, health related research, and fundamental science, e.g., understanding how living systems work. However, many biochemical reactions are characterized by a high degree of complexity that is due to the multiplicity of proton and metal-bound species. Thus, the result of an equilibrium measurement for biochemical reactions is generally an apparent equilibrium constant K?, as distinct from the standard equilibrium constant K. K? is written in terms of sums of species and is a function of temperature, pH, pX (X = H, Mg, etc.), and ionic strength. This is in contrast to the standard equilibrium constant, which is a function only of temperature and ionic strength.
One can use any suitable method, e.g. spectrophotometry and HPLC, to measure K? for an enzyme-catalyzed reaction. Calorimetry is also needed to fully characterize the thermodynamics of such reactions. Finally, equilibrium modeling calculations can be used to calculate values of the standard equilibrium constant, the Gibbs free energy, enthalpy and entropy changes for a chemical reference reaction that is written in terms of ionic species. The results of such experiments can be related to other thermodynamic measurements by means of thermodynamic network calculations. These calculations can be used to check the accuracy of the measurements and also serve to greatly leverage the utility of the results.
This seminar will give an overview of this field of research and include a discussion of the thermodynamic formalisms needed to describe the measurements, the methodology, several applications, theoretical calculations and estimation methods, and a database (http://xpdb.nist.gov/enzyme_thermodynamics/) that contains the literature and results in this field.
One can use any suitable method, e.g. spectrophotometry and HPLC, to measure K? for an enzyme-catalyzed reaction. Calorimetry is also needed to fully characterize the thermodynamics of such reactions. Finally, equilibrium modeling calculations can be used to calculate values of the standard equilibrium constant, the Gibbs free energy, enthalpy and entropy changes for a chemical reference reaction that is written in terms of ionic species. The results of such experiments can be related to other thermodynamic measurements by means of thermodynamic network calculations. These calculations can be used to check the accuracy of the measurements and also serve to greatly leverage the utility of the results.
This seminar will give an overview of this field of research and include a discussion of the thermodynamic formalisms needed to describe the measurements, the methodology, several applications, theoretical calculations and estimation methods, and a database (http://xpdb.nist.gov/enzyme_thermodynamics/) that contains the literature and results in this field.
