A new method for determining the phase in the X-ray diffraction structure analysis of phosphatidylcholine/alcohol

A new method based on a sampling theorem is proposed for determining the phase in the X-ray diffraction analysis of the structure of phospholipid systems. The thickness of a lipid layer is changed by changing the length of hydrocarbon chains in order to rebuild the continuous transform from the scattering amplitudes. By employing this method, the phases were accurately determined in a structure analysis of nine phospholipid/alcohol systems at the interdigitated gel phase. The nine systems are dimyristoylphosphatidylcholine(DMPC)/propanol, DPPC/methanol, DPPC/ethanol, DPPC/propanol, DPPC/butanol, distearoylphosphatidylcholine(DSPC)/methanol, DSPC/ethanol, DSPC/propanol and DSPC butanol systems.