Tethered bilayer lipid membranes, tBLMs, are biomimetic membranes
consisting of a lipid bilayer interposed between the aqueous solution
and a hydrophilic chain, called spacer, anchored to a metal electrode,
which are used to incorporate single peptides or membrane proteins, so
as to elucidate their structure-function relationships. Hg is a
particularly convenient supporting electrode material for tBLMs thanks
to its liquid state, which imparts to the lipid bilayer a fluidity and
lateral mobility comparable with that of biological membranes, but with
a much higher robustness and resistance to electric fields. The free
movement of lipid molecules enables mercury-supported tBLMs to react to
the presence of proteins, charges and physical forces in a dynamic and
responsive manner, mimicking the functionality of living cell membranes.
This review describes the way in which the structure of these tBLMs is
affected by the incorporation and functional activity of peptides and
small proteins and the mode of formation of ohmic or voltage gated ion
channels, by using electrochemical impedance spectroscopy,
potential-step chronocoulometry, cyclic voltammetry and phase-sensitive
AC voltammetry.