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Entropy-enthalpy Compensation of Biomolecular Systems in Aqueous Phase: a Dry Perspective
Liviu Movileanu1, Eric A Schiff
1Department of Physics, Syracuse University, Syracuse, New York USA.
Monatshefte Fur Chemie
|August 27, 2013
Summary
Entropy-enthalpy compensation is common in biological macromolecules. New models incorporating solvent relaxation and vibrational entropy suggest a lower compensation temperature in water, aiding in calculating bare Gibbs free energy changes.
Area of Science:
- Thermodynamics
- Biophysical Chemistry
- Chemical Physics
Background:
- Biological macromolecules in aqueous solution exhibit entropy-enthalpy compensation.
- This phenomenon is observed in processes like protein folding and ligand binding.
- Existing compensation temperatures average around 293 K.
Purpose of the Study:
- To survey thermodynamic measurements of biological macromolecule processes.
- To investigate the origins of entropy-enthalpy compensation.
- To develop a method for determining bare Gibbs free energy changes.
Main Methods:
- Analysis of thermodynamic data for protein folding/unfolding and ligand binding/unbinding.
- Incorporation of solvent relaxation effects into thermodynamic models.
- Inclusion of multi-excitation entropy from vibrational quanta.
Main Results:
- Entropy-enthalpy compensation was observed across various biological processes.
- A refined model incorporating solvent relaxation and vibrational entropy yielded a compensation temperature near 230 K in water.
- A general procedure for calculating bare Gibbs free energy changes was demonstrated.
Conclusions:
- Entropy-enthalpy compensation is a fundamental aspect of macromolecular behavior in solution.
- Solvent relaxation and vibrational entropy significantly influence compensation temperatures.
- The developed method allows for a more accurate determination of intrinsic thermodynamic properties.
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