ABSTRACT
Reversed micelle-containing organic solvents can be effective extractants for the recovery, purification, and concentration of proteins using traditional liquid-liquid extraction techniques. Factors governing the solubilization of proteins by these novel solvent systems include the electrostatic interactions between the proteins and the charged surfactant headgroups, and the aggregative properties of the surfactants in solution. Electrostatic interactions can be mediated by varying pH, ionic strength, and salt and buffer type. Solvent structure and surfactant type are important in determining the cooperative formation of the protein-micelle complex. Enhanced partitioning of selected proteins is obtained through the incorporation of biospecific affinity surfactants in the surfactant-solvent mixtures. This partitioning behavior has been described effectively in terms of simple phenomenological thermodynamic models. Applications of reversed micelles in the recovery of both intracellular and extracellular proteins have provided promising results. Efficient contacting of the two phases can be achieved using conventional mixer-settler systems, or the newer hollow-fiber membrane extractors.
