Bacteriorhodopsin-containing membrane fragments adorbed on mercury-supported biomimetic membranes

Membrane fragments containing bacteriorhodopsin (bR), a Light-driven proton pump, are adsorbed on mercury-supported biomimetic membranes. The biomimetic membranes consist in a phospholipid monolayer and an alkanethiol/phospholipid bilayer supported by a hanging mercury drop electrode. Once adsorbed on the lipid film, bR is activated by shining the mercury drop with an appropriate Light source, and the transient capacitive current generated by the ion pump is measured under short-circuit conditions and in the absence of photoartefacts. Our results show that the lipid-coated mercury electrode is suitable for adsorbing membrane fragments and, hence, for studying the electrochemical behaviour of protein in a biomimetic environment.