Electrophysiological interrogation of asymmetric droplet interface bilayers reveals surface-bound alamethicin induces lipid flip-flop.

摘要: Abstract The droplet interface bilayer (DIB) method offers simple control over initial leaflet compositions in model membranes, enabling an experimental path to filling gaps our knowledge about the interplay between compositional lipid asymmetry, membrane properties, and behaviors of membrane-active species. Yet, stability asymmetry DIBs has received very little attention, particularly presence peptides ion channels that are often studied DIBs. Herein, we demonstrate for first time parallel, capacitance-based measurements intramembrane potential with arrays asymmetric assembled a microfluidic device characterize many hours absence peptides. from opposing monolayers ester (DPhPC) ether (DOPhPC) forms diphytanoyl-phosphatidylcholine yielded bilayers were stable at least 18 h as indicated by |137 mV| potential. In contrast, addition surface-bound alamethicin caused gradual, concentration-dependent decrease magnitude dipole difference. Intermittent current-voltage revealed also shifts threshold voltage required drive peptide insertion channel formation. These outcomes take place course 1 5 h after formation, suggest promote flip-flop, even un-inserted, state, disordering lipids monolayer which they bind. Moreover, this methodology establishes use parallel electrophysiology efficiently studying