Characterization of Protein-Facilitated Ion-Transfer Mechanism at a Polarized Aqueous/Organic Interface
MetadataShow full item record
© 2019 American Chemical Society.
Protein electrochemistry studies at a polarized interface between two immiscible electrolyte solutions (ITIES) indicate that the detection mechanism of a protein at the interface involves a combination of protein-anion complexation and interfacial adsorption processes. A detailed characterization of the protein-facilitated mechanism of ion transfer at the ITIES will allow the development of new label-free biomolecular detection tools. Molecular dynamics simulations were performed to describe the mechanism of transfer of the hydrophobic anion tetraphenylborate (TPB-) from a 1,2-dichloroethane (organic) phase to an aqueous phase mediated by lysozyme as a model protein under the action of an external electric field. The anion migrated to the protein at the interface and formed multiple contacts. The side chains of positively charged Lys and Arg residues formed electrostatic interactions with the anion. Nonpolar residues like Trp, Met, and Val formed hydrophobic contacts with the anion as it moved along the protein surface. During this process, lysozyme adopted multiple, partially unfolded conformations at the interface, all involving various anion-protein complexes with small free-energy barriers between them. The general mechanism of protein-facilitated ion transfer at a polarized liquid-liquid interface thus likely involves the movement of a hydrophobic anion along the protein surface through a combination of electrostatic and hydrophobic interactions.
Showing items related by title, author, creator and subject.
Electrochemical behaviour of hen-egg-white lysozyme at the polarised water/1,2-dichloroethane interfaceScanlon, M.; Jennings, E.; Arrigan, Damien (2009)The electrochemical behaviour of hen-egg-white lysozyme (HEWL) was studied at the polarizedwater/1,2-dichloroethane interface. The voltammetric ion-transfer response was found to bedependent on the pH and ionic strength ...
Scanlon, M.; Strutwolf, J.; Arrigan, Damien (2010)The behaviour of two biological macromolecules, bovine pancreatic insulin and hen-egg-whitelysozyme (HEWL), at aqueous-organogel interfaces confined within an array of solid-state membrane micropores was investigated via ...
Interaction of surface-attached haemoglobin with hydrophobic anions monitored by on-line acoustic wave detectorEllis, J.; Xu, S.; Wang, X.; Herzog, G.; Arrigan, Damien; Thompson, M. (2010)The behaviour of proteins on surfaces and at interfaces is an important field with applications in drugdevelopment, clinical diagnostics and studies of device biocompatibility. A key factor is the conformation ofsurface-bound ...