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

Membrane fragments containing bacteriorhodopsin (bR), a Light-driven proton pump, are adsorbed on mercury-supported biomimetic membranes. The biomimet ic membranes consist in a phospholipid monolayer and an alkanethiol/phospho lipid bilayer supported by a hanging mercury drop electrode. Once adsorbed on the lipid film, bR is activated by shining the mercury drop with an appr opriate 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 ele ctrochemical behaviour of protein in a biomimetic environment. (C) 1999 Els evier Science S.A. All rights reserved.