Reconstitution of an ATP-mediated Active Transport System across Black Lipid Membranes

Abstract

IN general, concentration gradients across the membranes of living cells for a number of substances, including ions and essential metabolites such as sugars and amino-acids, are maintained through transport processes driven by an energy supply other than the electrochemical gradient of the transported species. Characteristically, such transport processes involve vectorial transport of the species concerned, a stoichiometric coupling between the energy supply and transport reactions and localization of the transport system in the asymmetric environment which it maintains, usually the membrane phase.