Wet Lipid-Protein Membranes Imaged at Submolecular Resolution by Atomic ForceMicroscopy

摘要

We have employed an atomic force microscope (AFM) to determine the structuralproperties of supported planar membranes and membrane-bound proteins in an aqueous environment. Images of an asymmetric Langmuir Blodgett film of a charged phospholipid show long range positional as well as orientational order; individual headgroups are resolved. In order to study bifunctional membranes we have employed a recently introduced technique that allows the controlled formation of planar lipid-protein membranes on solid supports from a vesicle suspension. Combining this technique with the AFM permits the nondestructive imaging of these models of cell membranes at molecular resolution under physiological conditions of ionic strength and temperature.