Fig. 3.

Atomic force microscopy images of MPEG1 on supported lipid bilayers consisting of E. coli total lipid extract. a Without (-GA) and b with (+ GA) glutaraldehyde fixation, at neutral pH. c Increasing the concentration of MPEG1 results in a high-density, hexagonal packing on the supported bilayer. The dynamic motion observed in a is therefore reduced, such that the MPEG1 assemblies could be well resolved without glutaraldehyde fixation. Shown below each AFM images are 1D height profiles extracted from selected regions (blue lines) where both membrane and MPEG1 prepores are observed. When packed in dense hexagonal lattice, the MPEG1 assemblies mostly occlude the membrane from the AFM probe, resulting in a smaller height variation (until a region of bare membrane is encountered). Scale bar: 200 nm. Colour (height) scale: 16 nm