Fusion of Liposomes to Planar Bilayers

Abstract

During the late 1970s and early 1980s, methods to reconstitute integral membrane channel-forming proteins into planar membranes were developed. There are now two basic strategies. The first is to fuse vesicles that contain channels to preformed phospholipid planar membranes (Miller and Racker, 1976; Cohen et al., 1980; Akabas et al., 1984). The vesicles can be those obtained by the usual methods of cell fractionation—homogenization and centrifugation— and are often referred to as “native” vesicles, or they can be phospholipid vesicles that have had a purified channel incorporated into the vesicular membrane, known as “artificial” vesicles. The second strategy is to incorporate membrane channels into monolayers derived from vesicles (Verger and Pattus, 1976; Pattus et al., 1981; Schindler, 1979) and to form bilayers with functional channels from these monolayers (Schindler and Rosenbusch, 1978; Schindler and Quast, 1980; Nelson et al., 1980; Vodyanoy and Murphy, 1982; Coronado and Latorre, 1983). Either native or artificial vesicles can be used to form the monolayers.