A structural and kinetic study by energy dispersion X-ray diffraction: interaction between 1,4-dihydropyridines and biological membranes

Application of energy dispersive X-ray diffraction to the study of the main transition phase of the pure and doped DMPC (L alpha-dimyristoylphosphotidylcholine; 1,2-ditetradecanoyl-sn-glycero-3-phosphatidylcholine) bilayers is reported. The aim is to provide an investigative tool to follow the structural variation induced in these systems by temperature and by insertion of doping substances. Hydrophobic compounds such as 1,4-dihydropyridines are used as doping molecules; Nifedipine and Lacidipine show different physical-chemical properties, modifying in a different way the membrane bilayer and its main transition phase. The results show that this technique is useful for studying these kinds of systems (membrane bilayer or biopolymer), giving information on structural variations that occur in a relatively short time. (C) 1998 Elsevier Science B.V.