Differential Scanning Calorimetry of Proteins and the Two-State Model: Comparison of Two Formulas

Abstract

Differential Scanning Calorimetry (DSC) is a regular and powerful tool to measure the specific heat profile of various materials. In order to connect the measured profile to the properties of a particular protein, a model is required to fit. We discuss here the application of an exact two-state formula with its approximation and process the DSC experimental data on protein folding in water. The approximate formula relies on the smallness of the transition interval, which is different for each protein. With an example of the set of 33 different proteins, we show the practical validity of the approximation and the equivalence of exact and approximate two-state formulas for processing DSC data.

Keywords

• protein folding
• Differential Scanning Calorimetry
• heat capacity
• two-state model
• Hawley model