THERMODYNAMICS OF UBIQUITIN UNFOLDING

The energetics of ubiquitin unfolding have been studied using differen tial scanning microcalorimetry. For the first time it has been shown d irectly that the enthalpy of protein unfolding is a nonlinear function of temperature. Thermodynamic parameters of ubiquitin unfolding were correlated with the structure of the protein. The enthalpy of hydrogen bonding in ubiquitin was calculated and compared to that obtained for other proteins. It appears that the energy of hydrogen bonding correl ates with the average length of the hydrogen bond in a given protein s tructure. (C) 1994 Wiley-Liss, Inc.