MACROMOLECULE HYDRATION AND THE EFFECTS OF SOLUTES ON THE CLOUD POINT OF AQUEOUS SOLUTIONS OF POLYVINYL METHYL ETHER: A POSSIBLE MODEL FOR PROTEIN DENATURATION AND TEMPERATURE CONTROL IN HOMEOTHERMIC ANIMALS.

The effect of strong, neutral, 11 electrolytes MgSO4 area, tetraalkylammonium salts, succrose and alcohols on the cloud point temperature of aqueous solutions of polyvinyl methyl ether have been examined and are interpreted in terms of 1 the two types of water structure, coulombic and hydrophobic, comprising the hydration sheath of polymer, 2 the selective exclusion of solute from the polymers hydration sheath, and 3 the solutes stabilization or destabilization of the polymers hydration sheath. The last two of these processes are related to the viscosity B-coefficient of the solute ions. The behavior of the polymer exhibits both similarities to and differences from proteins, and caution must be exercised in the use of the cloud point phenomenon as a model of protein denaturation. The solute effects suggest a possible experimental test of the hypothesis that the thermal destruction of a biopolymers hydration sheath might provide the basis of temperature control in homeothermic animals. Author