4 research outputs found
Phase state dependent current fluctuations in pure lipid membranes
Current fluctuations in pure lipid membranes have been shown to occur under
the influence of transmembrane electric fields (electroporation) as well as a
result from structural rearrangements of the lipid bilayer during phase
transition (soft perforation). We demonstrate that the ion permeability during
lipid phase transition exhibits the same qualitative temperature dependence as
the macroscopic heat capacity of a D15PC/DOPC vesicle suspension. Microscopic
current fluctuations show distinct characteristics for each individual phase
state. While current fluctuations in the fluid phase show spike-like behaviour
of short time scales (~ 2ms) with a narrow amplitude distribution, the current
fluctuations during lipid phase transition appear in distinct steps with time
scales in the order of ~ 20ms. 1 We propose a theoretical explanation for the
origin of time scales and permeability based on a linear relationship between
lipid membrane susceptibilities and relaxation times in the vicinity of the
phase transition.Comment: 22 pages including 6 figure