AFFINITY-BASED REVERSED MICELLAR PROTEIN EXTRACTION .1. PRINCIPLES AND PROTEIN LIGAND SYSTEMS

Affinity cosurfactants, consisting of hydrophilic ligands derivatized with hydrophobic tails, increase the efficiency of selective protein r ecoveries using reversed micelles by extending the operating range of pH and salt concentration over which an extraction can be performed. T hree different affinity cosurfactant-protein pairs have been used to d emonstrate the principles of this extractive technique: (i) concanaval in A, a lectin, was extracted with the addition of octyl glucoside; (i i) natural amphiphiles, such as lecithin, were used to extract myelin basic protein, a membrane-associated protein known to recognize and bi nd the phosphatidylcholine headgroup; and (iii) alkyl boronic acids we re used to extract chymotrypsin. The enhancement in protein transfer c orrelated with the binding strength of the free ligand and protein in aqueous solution. Several control studies confirmed the biospecificity of the interactions of protein and affinity cosurfactant. (C) 1993 Jo hn Wiley & Sons, Inc.