Electrochemical Extraction of Proteins by Reverse Micelle Formation

Electrochemical Aspects of the Reverse Micelle Extraction of Proteins

“…The tetrapentylammonium salt of AOT (TPnAAOT) was prepared from the sodium salt (NaAOT; Tokyo Kasei Kogyo) according to a previous procedure. 26 The preparation and purification of tetrapentylammonium tetraphenylborate (TPnATPB) and the preparation of an aqueous solution of tetrapentylammonium chloride (TPnACl) were described previously. 27 DCE for HPLC was purchased from Wako Pure Chemical Industries and used as received.…”

“…26 28 (Hokuto Denko, HA10100mM1A), which was equipped with a positive-feedback circuit for IR compensation. Unless noted otherwise, the following electrochemical cell was used:…”

“…These extraction behaviors of Cyt c at the higher and lower pH values were in accordance with those reported previously. 26 The measurement shown in Fig. 2(a) was made using DCE containing 20% (v/v) isooctane as the O-phase solvent.…”

“…[22][23][24][25][26] Vagin et al 22 first reported spontaneous micelle formation at a polarized O/W interface in the presence of anionic surfactants [Aerosol-OT (AOT); bis(2-ethylhexyl)sulfosuccinate]. They further tried to apply the system to the interfacial transport of proteins, but did not achieve successful results.…”

“…They further tried to apply the system to the interfacial transport of proteins, but did not achieve successful results. More recently, our group 26 used the tetrapentylammonium salt of AOT (not the commercial sodium salt as previously) 22 to extract the colored protein cytochrome c (Cyt c) to 1,2-dichloroethane (DCE) via reverse micelle formation under controlling the Galvani potential difference of the interface. This was successful, however, when the W phase was neutral (pH 7); when it was acidic (pH 3.4), the protein could not be extracted into the O phase, but the protein-surfactant complexes were found to aggregate at the O/W interface.…”