Localization of dibromophenol in DPPC/water liposomes studied by anomalous small-angle X-ray scattering

The localization of 2,4-dibromophenol molecules along the bilayer normal was investigated by anomalous small-angle X-ray scattering (ASAXS) with synchrotron radiation. The ASAXS measurements, executed at three different energies, provide the separation of the scattering of the bromine atoms of dibromophenol molecules from that of the whole system. Using a full q-range model, the localization of the dibromophenol molecules was characterized at a lower (0.1) and a higher (1) dibromophenol/lipid molar ratio corresponding to the gel and to the interdigitated phases of the vesicle matrix, respectively.