Valinomycin-mediated transport of alkali cations through solid supported membranes

Melting and interdigitation of microstructured solid supported membranes quantified by imaging ellipsometry

“…[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] However, little is known about the impact of the solid support on physical properties of lipid bilayers attached to surfaces such as the main phase transition temperature or lateral mobility of the lipids. It is expected that phase transitions are strongly affected if not entirely suppressed by the various different supports ranging from glass, gold, silicon, mica to all kinds of functionalized surfaces.…”

4 Electrochemistry of Biomimetic Membranes

“…Upon incorporating valinomycin in the tBLM, the impedance spectrum was fitted to an equivalent circuit consisting of three circuit elements in series: a capacitance C s simulating the spacer, a R m C m mesh simulating the lipid bilayer, and a resistance R  , simulating the aqueous solution. 161,169 In a KCl solution, the conductance, 1/R m , of the lipid bilayer moiety was found to increase proportionally to the bulk valinomycin concentration, c v . The lipid bilayer capacitance, C m , remained practically constant with varying c v using the DPTL thiolipid 169 , but increased linearly with c v using a different thiolipid.…”

“…TBLMs fabricated with polyethyleneoxy-base thiolipids exhibit capacitances in the range from 0.5 to 0.7 F cm -2 and resistances in the range from 5 to 10 M cm 2 , which are comparable with the values found for conventional BLMs; however, somewhat higher capacitance values (1 F cm -2 ) have been reported for long spacers. 161 A particularly convenient tBLM of this type, called DPTL, was synthesized in the Max Planck Institute of Polymer Science in Mainz. 1 It consists of a hydrophilic tetraethyleneoxy chain covalently linked to a lipoic acid residue for anchoring to the metal at one end, and bound via ether linkages to two phytanyl chains at the other end (see Fig.…”

Membrane Electrochemistry: Electrochemical Processes in Bilayer Lipid Membrane

“…In an attempt to overcome the drawbacks of psBLM, sBLM and BLM, while preserving the stability provided by the covalently bound alkanethiol monolayer, so-called thiolipids have been synthesized [52,[56][57][58][59]. The thiolipids are composed of lipid derivatives, extended at their polar headgroups by hydrophilic spacers, which terminate in a thiol or disulfide group for covalent binding to the substrate.…”

“…Such bilayers exhibit a very high membrane resistance. Steinem et al [68] used different spacer and vesicle fusion technique to form a bilayer membrane with 0.8-1.0 μFcm -2 capacitance. Knoll and co-workers [58,63] were the first to introduce to use oligopeptide sequences as hydrophilic spacers attached to the head group of lipid, resulting in the formation of peptide-tethered bilayers.…”