Fig. 2: The addition of polymyxin to OMV membranes induces hexagonal assemblies.
From: Reply to: Antibiotics and hexagonal order in the bacterial outer membrane
AFM height images of multiple membranes of OMVs recorded in buffer solution at room temperature. Each OMV membrane is shown before and after the addition of polymyxin. White boxes indicate where AFM height images were recorded to show the appearance of the membrane surface at higher resolution. The absence of structural details indicates that the membrane regions were either devoid of OMPs and contained mainly lipids or that OMPs could not be resolved. Indicative of adding polymyxin to OMV membranes is that they reduce thickness, increase surface area and are covered entirely with hexagonal lattices. OMVs from E. coli MG1655 WT strain, the AFM sample preparation, and the AFM imaging were prepared as described1. The brightness range of the AFM height images corresponds to a vertical range of 18 nm (overviews) and 2 nm (zoom ins). Scale bars, 200 nm (overviews) and 20 nm (zoom ins).
