Bacteriorhodopsin - an Archaea (Halobacteria) proton pump...       it captures light energy, using it to move protons across the membrane out of the cell.       The resulting proton gradient is subsequently converted into chemical energy via ATP synthesis.                               animation of bacteriorhodopsin action*
in the artificial vesicles bactriorhodopsin                                                                                   is used to create artificial proton gradient
back	Racker, E., and Stoeckenius, W. (1974) Reconstitution of purple membrane vesicles catalyzing light-driven proton uptake and adenosine triphosphate formation. J. Biol. Chem. 249, 662–663