HYDROPHOBIC ION-PAIRING - ALTERING THE SOLUBILITY PROPERTIES OF BIOMOLECULES

The high aqueous solubility of ionic compounds can be attributed to th e ease of solvation of the counter ions. Replacement of the counter io ns with ionic detergents dramatically alters the solubility properties of the molecule. Not only does the aqueous solubility drop precipitou sly, but the solubility in organic phases increases as well. Consequen tly, the partition coefficient changes by orders of magnitude. This io n pairing phenomenon, which we term hydrophobic ion pairing (HIP), has been extended to polyelectrolytes, such as proteins and polynucleotid es, These materials form HIP complexes that dissolve in a range of org anic solvents, often with retention of native structure and enzymatic activity. The HIP process has been used to purify protein mixtures, co nduct enzymatic reactions in nonaqueous environments, increase structu ral stability, enhance bioavailability, and prepare new dosage forms.