Interfacial Complexes between a Protein and Lipophilic Ions at an Oil-Water Interface

• Published in: Analytical Chemistry -Washington DC- (ISSN: 0003-2700), vol. 82, num. 18, p. 7699–7705
• American Chemical Society, 2010

The interaction between an intact protein and two lipophilic ions at an oil-water interface has been investigated using cyclic voltammetry, impedance based techniques and a newly developed method in which the biphasic oil-water system is analyzed by biphasic electrospray ionization mass spectrometry (BESI-MS), using a dualchannel electrospray emitter. It is found that the protein forms interfacial complexes with the lipophilic ions and that it specifically requires the presence of the oil-water interface to be formed under the experimental conditions. Furthermore, impedance based techniques and BESI-MS with a common ion to polarize the interface indicated that the Galvani potential difference across the oil-water interface significantly influences the interfacial complexation degree. The ability to investigate protein-ligand complexes formed at polarized liquid-liquid interfaces is thus a new analytical method for assessing potential dependent interfacial complexation using a structure elucidating detection principle.

Keywords: Ionization Mass-Spectrometry ; Liquid-Liquid Interfaces ; Redox-Inactive Proteins ; Electrospray-Ionization ; Liquid/Liquid Interfaces ; Electrochemical-Behavior ; Electrolyte-Solutions ; Gibbs Energies ; Solid-Surfaces ; Esi-Ms

Reference

• EPFL-ARTICLE-165735
• doi:10.1021/ac101528r
• View record in Web of Science

Record created on 2011-05-11, modified on 2012-03-21