[Protein stability and hydrophobic interactions]

The paper summarizes results of calorimetric studies of protein denaturation and of dissolution of non-polar substances in water. The analysis of the available experimental data shows that the positive contribution of the hydrophobic interactions in stabilization of the protein compact state is due to van der Waals interactions between the protein non-polar groups, while the contribution of water solvation by these groups, in spite of the widely spread opinion, appears to be always negative. This destabilizing action of water solvation on the protein increases as the temperature decreases, and at a significantly low temperature causes unfolding of the compact structure of protein, i. e. cold denaturation.