Mechanics of biomimetic free-standing lipid membranes: insights into the elasticity of complex lipid compositions.

The creation of free-standing lipid membranes has been so far of remarkable interest to investigate processes occurring in the cell membrane since its unsupported part enables studies in which it is important to maintain cell-like physicochemical properties of the lipid bilayer, that nonetheless depend on its molecular composition. In this study, we prepare pore-spanning membranes that mimic the composition of plasma membranes and perform force spectroscopy indentation measurements to unravel mechanistic insights depending on lipid composition. We show that this approach is highly effective for studying the mechanical properties of such membranes.

Photoactivation of Cell-Free Expressed Archaerhodopsin-3 in a Model Cell Membrane.

Transmembrane receptor proteins are located in the plasma membranes of biological cells where they exert important functions. Archaerhodopsin (Arch) proteins belong to a class of transmembrane receptor proteins called photoreceptors that react to light. Although the light sensitivity of proteins has been intensely investigated in recent decades, the electrophysiological properties of pore-forming Archaerhodopsin (Arch), as studied in vitro, have remained largely unknown.

Simultaneous measurement of surface and bilayer tension in a microfluidic chip.

Freestanding lipid bilayers are one of the most used model systems to mimic biological cell membranes. To form an unsupported bilayer, we employ two aqueous fingers in a microfluidic chip surrounded by an oily phase that contains lipids. Upon pushing two aqueous fingers forward, their interface becomes decorated with a lipid monolayer and eventually zip to form a bilayer when the monolayers have nanoscopic contact with each other.