DIFFERENT VIEWS ON THE STABILITY OF PROTEIN CONFORMATIONS AND HYDROPHOBIC EFFECTS

Apparently contradictory statements about the thermodynamics of aqueou s protein solutions and of hydrophobic effect are quoted and discussed . Some credibility is found in the divergent points of view and it is pointed out that they focus attention on different aspects of the comp licated conditions in aqueous solutions, some of which are more import ant than others for the stability of protein conformations. The import ance of characteristics of solvent water is emphasized, in particular (1) the strong mutual cohesion of water molecules, and (2) structural changes of water induced by (nonpolar) solute molecules. It is stresse d that consideration of only one of these effects and an inexpedient c hoice of standard states are origins of confusion in the literature ab out aqueous systems. A simple approach to hydrophobic effects consider ing both of the above mentioned effects, is proposed.