ENTHALPY CONVERGENCE TEMPERATURES - PROTEINS AND MODEL COMPOUNDS

It is suggested that the classical model of non-polar hydration in pro teins does not take into account a large negative enthalpy due to the solvation of polar surface, mostly represented by the peptide group. A nalysis of the dissolution thermodynamics of several organic compounds , containing functional groups typical of proteins, clarifies that the penalty associated with the burial of polar surface in proteins shift s the temperature at which the water transfer enthalpy of non-polar mo ieties goes to zero, from room temperature to approx. 376 K. This seem s to be the clue for reconciling opposing views on the role played by non-polar hydration in proteins.