(156a) Protein Extraction and Chiral Separation Utilizing Biomimetic Liquid Membranes

Reversed micelles create a unique environment in organic media, capable of solubilizing hydrophilic biomolecules (e.g., proteins, peptides, amino acids, and DNA) within their aqueous interior. This feature enables the practical use of biomaterials in organic media because reversed micelles solubilize them while maintaining their intrinsic activity. In this study, we focus on two topics: protein extraction and chiral separation of biomolecules using a biomimetic liquid membrane. Regarding protein extraction, recent attempts to extract proteins from an aqueous solution into isooctane using reversed micelles are presented, and some important operational parameters necessary for efficient protein transfer are discussed. Furthermore, a novel function of reversed micelles as a protein activation medium is introduced, demonstrating that denatured proteins can be completely reactivated in the reversed micellar solution. Concerning chiral separation, we have discovered that a supported liquid membrane (SLM) encapsulating enzymes exhibits high enantioselectivity (i.e. over 96%) in transporting the racemic pharmaceutical compound ibuprofen. While SLMs have been widely studied as a selective separation technique, their application has primarily been limited to the separation of metal ions. By employing ionic liquids as the liquid membrane phase, we achieve the stabilization of the SLM, as ionic liquids have negligible vapor pressure and are water-immiscible. In our study, we successfully demonstrate the enantioselective transport of the (S)-enantiomer from racemic ibuprofen through a lipase-facilitated SLM based on ionic liquids. We have also developed an enzyme-encapsulated SLM for the optical resolution of an organic acid. In this setup, a lipase encapsulated within the liquid membrane phase recognizes the (S)-isomer of the substrate organic acids, allowing selective permeation of this (S)-isomer through the SLM. Essentially, the enzyme in the SLM serves as a chiral selector in the membrane separation process.