Solubilization and reconstitution of the melibiose carrier from a plasmid-carrying strain of Escherichia coli.

A strain of EScherichia coli was constructed containing a plasmid from the Clarke-Carbon collection that showed high levels of melibiose transport activity. Membranes from the plasmid-containing strain were extracted with octyl-beta-D-glucopyranoside and melibiose transport was reconstituted in liposomes. The proteoliposomes exhibited counterflow activity, as well as membrane potential and sodium gradient-driven melibiose accumulation.