[30] Insertion of lipids and proteins into bacterial membranes by fusion with liposomes

This chapter discusses the insertion of lipids and proteins into bacterial membranes by fusion with liposomes. Cytoplasmic membrane vesicles derived from Escherichia coli and many other bacteria provide a well-defined model system to study membrane- associated energy-transducing processes. A method has been developed in our laboratory that allows the fusion-mediated insertion of a variety of delta p-generating systems into bacterial membranes while energy conserving properties of the membrane are retained. These procedures also are used for the bulk enrichment of the bacterial membrane with exogenous lipids. Principles of this method and specific details of its applications in studies on the mechanism of solute translocation and lipid protein interactions in lactic acid bacteria are described in this chapter.