Electrical oscillation and fluctuation in phospholipid membranes

Rationalizing the membrane interactions of cationic amphipathic antimicrobial peptides by their molecular shape

“…The resulting small and transient openings suffice for the diffusion of smaller molecules, including the peptides themselves in and out of the cell interior [50] and can explain the step-wise changes in conductivity that have been monitored for magainin 2 or for cecropins [45][46][47]. Interestingly, similar conductivity increases have also been observed in the presence of detergents [61,62], in pure lipid membranes [63][64][65], or when small unilamellar phospholipid vesicles are added to planar lipid bilayers [66].…”

Structure and Function of Membrane-Lytic Peptides

“…In this case the high local electric fields are sufficient for transient pore formation (Miteva et al, 1999). Interestingly, stepwise conductivity increases have also been observed in the presence of detergents (Schlieper and De Robertis, 1977;Alder et al, 1991), pure lipid membranes (Antonov et al, 1980;Kaufmann and Silman, 1983;Yoshikawa et al, 1988), or small unilamellar phospholipid vesicles when added to planar lipid bilayers (Woodbury, 1989).…”

Pure lipid vesicles can induce channel-like conductances in planar bilayers

“…Another possible explanation for LICS is that they are related to spontaneous bilayer fluctuations previously reported (Boheim, Hanke & Eibl, 1980;Yoshikawa et al, 1988). These fluctuations are attributed to boundary defects in the bilayer due to phase domains.…”

“…It is also noteworthy that the reported bilayer fluctuations require conditions that LICS do not. Yoshikawa et al (1988) reported that fluctuations were observed only when the bilayer was made from lipids with unsaturated chains. Boheim et al (1980) Thus, LICS are not explained by a mechanical disturbance, nonlipid contaminants, or lipid boundary defects.…”