Figure 1.

Gramicidin incorporation is similar in symmetric and asymmetric liposomes. (A) Experimental SAXS form factors of a series of POPC gA-sLUVs with an increasing concentration of gA and isotopically asymmetric LUVs, gA-s^∗LUV, composed of deuterated variants of POPC and prepared with a nominal gA/lipid ratio of 1:40. The cartoon schematic next to the figure legend represents an isotopically asymmetric gA-s^∗LUV. All measurements were performed at 25°C. (B) SAXS form factors calculated from Monte Carlo simulations of a POPC vesicle with different concentrations of gA (see Supporting Materials and Methods). The increase in the intensity at the minimum between the first and second scattering lobes with increasing gA concentration (shown in an expanded view in the inset) is caused by the electron density contrast between the lipid bilayer and the membrane-spanning gA dimers. To see this figure in color, go online.