Electron micrographs of FVIII bound to DOPS/DOPC liposomes.

Open arrows indicate side-on views of membrane-attached FVIII molecules. In panels A and C, dashed line areas where the protein molecules are clearly visible on the liposome edges are contoured. Closed arrows show 2D arrays of FVIII molecules. The black star indicates the ‘naked’ liposomes, without attached FVIII, showing the cooperative effect of FVIII binding. Scale bar is 100 nm.