Hydrophobic hydration amount

Competition for Hydration Between Apolar (Hydrophobic) and Polar (e.g., Charged) Groups Controls Amount of Hydrophobic Hydration... 

As expected, the more hydrophobic Model Protein ii of Table 5.5, with two Val (V) residues replaced by two more hydrophobic Phe (F) residues every six pentamers, is shown in Figure 5.25B to exhibit more hydrophobic hydration. Again, as -CH2-CH2-COO forms on increasing the pH, the amount of hydrophobic hydration decreases. We conclude that the formation of carboxylate groups destructures hydrophobic hydration. Furthermore, the pH at which half of... 

Figure 5.27. Development of hydrophobic hydration, Nu, on ion pairing shows a mirrored decrease in, or lowering of T,. (Top) For the less hydrophobic Model Protein ii, the increase in JVm is somewhat modest as is the decrease in the value of T,. (Bottom) For the more hydrophobic Model Protein I, the increase in iV is very abrupt and the lowering of the value of T, is correspondingly abrupt. Conclusions (1) Amount of hydrophobic hydration, IV positions...

Above, the special structural organization of these model proteins provided the unique opportunity to identify and observe the behavior of hydrophobic hydration. Under relevant circumstances hydrophobic hydration was more prevalent than bulk water. Key variables showed that the amount of hydrophobic hydration, Nhh, determined T,. Numerous systematic studies, however, preceded the direct observation of hydrophobic hydration by microwave... 

Even though there is an increase in the amount of water in the elastomer on stretching, much of which must be hydrophobic hydration, the formation of carboxylates has become disfavored. Therefore, water of hydrophobic hydration must not be suitable for hydration of carboxylates. 

If this were not the case we would be faced with the puzzling question. Since the value of T, is higher when there are fewer CH2 units in the polymer, and therefore less hydrophobic hydration, why should a higher temperature be required to melt the lesser amount of more poorly structured hydrophobic hydration The thermally-induced inverse temperature transition does not result from a thermal destructuring of hydrophobic hydration, as we, with others, have indicated in the past (See for example the upper right illustration in Figure 2.8). ... 

Recall from Figure 5.27 and associated discussion that, as the amount of hydrophobic hydration increases, the value of T, decreases. The cusp of insolubility moves to lower temperatures, from above to below physiological temperature. Accordingly, hydrophobic association between two surfaces occurs because the surfaces are sufficiently hydrophobic that during a transient opening so much hydrophobic hydration forms that the T,-divide is below the operating temperature. This causes the transiently... 

The Amount of Hydrophobic Hydration on Potentially Complementary Surfaces Determines Whether Hydrophobic Association or Dissociation Occurs... 

---