Zwitterionic dipoles as a dielectric probe for investigating head group mobility in phospholipid membranes

摘要: Abstract For phospholipid membranes with zwitterionic head groups, the dipole can be considered as a specific label for tracing changes in dynamic behaviour of this region bilayer its various phases. Measurements dielectric properties fully hydrated 1,2-dipalmitoyl- sn -glycero-3-phosphocholine bilayers frequency range 1–50 MHz show dispersion which is attributed to motion phosphocholine dipoles plane bilayers. When temperature varied, both permittivity and loss factor increase sharply at pretransition (35°C) main transition (42°C). The relaxation time amplitude were also determined these further reflect structural occurring temperature. times varied between 4 ns 30°C 2.3 50°C. Due steric hindrances restriction angle group rotation occurs lower temperatures but greatly reduced above transition.