Entropy calculations on a reversibly folding peptide: changes in solute free energy cannot explain folding behavior
Related Experiment Video
Updated: Oct 9, 2026

Thermodynamics of Membrane Protein Folding Measured by Fluorescence Spectroscopy
Published on: April 28, 2011
1Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH Zentrum, Zurich, Switzerland.
Abstract:
The configurational entropy of a beta-heptapeptide in solution at four different temperatures is calculated. The contributions of the backbone and of the side-chain atoms to the total peptide entropy are analyzed separately and the effective contribution to the entropy arising from correlations between these terms determined. The correlation between the backbone and side-chain atoms amounts to about 17% and is rather insensitive to the temperature. The correlation of motion within the backbone and within side-chains is much larger and decreases with temperature. As the peptide reversibly folds at higher temperatures, its change in entropy and enthalpy upon folding is analyzed. The change in entropy and enthalpy upon folding of the peptide alone cannot account for the observed change in free energy on folding of the peptide in solution. Enthalpic and entropic contributions of the solvent thus also play a key role. Proteins 2001;43:45-56.
Related Concept Videos
Protein Folding
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Folding
Protein Folding
Molecular Chaperones and Protein Folding
The...
Molecular Chaperones and Protein Folding
The...
Standard Entropy Change for a Reaction

