title: Meet me on the other side: trans-bilayer modulation of a model voltage-gated ion channel activity by membrane electrostatics asymmetry.
abstract: While it is accepted that biomembrane asymmetry is generated by proteins and phospholipids distribution, little is known about how electric changes manifested in a monolayer influence functional properties of proteins localized on the opposite leaflet. Herein we used single-molecule electrophysiology and investigated how asymmetric changes in the electrostatics of an artificial lipid membrane monolayer, generated oppositely from where alamethicin--a model voltage-gated ion channel--was added, altered peptide activity. We found that phlorizin, a membrane dipole potential lowering amphiphile, augmented alamethicin activity and transport features, whereas the opposite occurred with RH-421, which enhances the monolayer dipole potential. Further, the monolayer surface potential was decreased via adsorption of sodium dodecyl sulfate, and demonstrated that vectorial modification of it also affected the alamethicin activity in a predictive manner. A new paradigm is suggested according to which asymmetric changes in the monolayer dipole and surface potential extend their effects spatially by altering the intramembrane potential, whose gradient is sensed by distantly located peptides.
authors: Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, Iasi, Romania.
authors: Loredana
authors: L
authors: Mereuta
authors: Alina
authors: A
authors: Asandei
authors: Tudor
authors: T
authors: Luchian
mesh_terms: D000408:Alamethicin / Q000737:chemistry; D004594:Electrophysiology; D007473:Ion Channels / Q000737:chemistry*; D008567:Membranes, Artificial; D010695:Phlorhizin / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D055672:Static Electricity
chemical_list: D007473:Ion Channels; D008567:Membranes, Artificial; D000408:Alamethicin; D012967:Sodium Dodecyl Sulfate; D010695:Phlorhizin