Transport behavior of protein in bulk liquid membrane using reversed micelles

Transport of lysozyme through a liquid membrane of reversed micelles of aer osol-OT (AOT) was studied. The feed phase was aqueous KCI or NaCl solution of lysozyme, and the recovery phase was aqueous KCI or BaCl2 solution, whil e the membrane is the solutions of AOT with or without contacting the feed solution. The cations in feed phase are transferred through the liquid memb rane and this cation transfer affects that of lysozyme and the size of reve rsed micelles of the membrane phase. Following transfer mechanisms have bee n proposed for the three systems investigated: the system NaCl-KCl, for whi ch formation of large aggregates in the membrane phase was observed, has a so flexible interface that the micelles could become unstabilized in the me mbrane phase. For KCl-BaCl2 system, the divalent ion Ba2+ is selectively an d excessively adsorbed on the interface and the negatively charged lysozyme molecules may be re-extracted at the interface of the recovery side by the electrostatic interaction with the adsorbed Ba2+ ions. Both sides of the i nterfaces of the system KCI-KCI have an adequate flexibility that extractio n and back-extraction of lysozyme through the membrane are attainable, alth ough the transfer rate is rather low. (C) 2002 Elsevier Science B.V. All ri ghts reserved.