Response functions of proteins

The thermodynamics of protein folding can be studied by a variety of differ ent techniques such as differential scanning calorimetry, differential scan ning densimetry and sound velocity measurements. These three methods monito r the different response functions heat capacity, expansion coefficient and compressibility that characterise various aspects of protein dynamics such as equilibrium energy and volume fluctuations and energy-volume correlatio ns. For the development of a comprehensive thermodynamic description of pro tein behaviour information on these response functions should be combined. As a starting point we provide in the present paper analytical solutions fo r the determination of the response functions and demonstrate on several ex amples how to extract a maximum of thermodynamic information on proteins fr om the measurements of C-p, alpha(p) and kappa(T). (C) 2000 Elsevier Scienc e B.V. All rights reserved.