Mechanism of detergent induced formation of striated structures in lipid vesicles

Small angle X-ray scattering measurements and cryo-transmission electron microscopy images have revealed that detergents such as Triton X-100 (TX-100) and n-Dodecyl-beta-Maltoside (DDM) can induce the formation of highly ordered structured in both DPPC, the main constituent of pulmonary surfactants, and DMPC. SAXS reveals that at temperatures below room temperature, TX-100 and DDM added to DPPC or DMPC vesicles causes Bragg peaks to appear bilayer scattering, along with a change in the overall morphology of the vesicle structures. Cryo-TEM measurement were performed on the TX-100 mixtures, revealing what appears to be striation of the bilayer or bundles of folded lamellae. To further investigate the mechanism of how these structures are actually formed, we propose a series of time-resolved X-ray scattering experiments which would reveal any intermediate structures that are forming at different low temperatures.