Abstract
We give comments on the interaction between macromolecules such as proteins immersed in aqueous solution. The translational motion of solvent molecules makes a large contribution to the dimerization free energy of macromolecules. The conventional theory of osmotic pressure for discussing the cosolute effect is applicable only to limited phenomena. We suggest phenomenological equations which incorporate the contribution from the translational motion of solvent molecules. At the same time, the problems of those equations are pointed out on the basis of the results from an elaborate statistical-mechanical theory. A calorimetrical approach for molecular recognition and structure formation of nano-materials is also discussed.
