Ea. Korepanova et al., Polymyxin B and Ca2+ induce conductivity fluctuations in bilayer lipid membranes from dipalmitoylphosphatidic acid, BIOFIZIKA, 45(2), 2000, pp. 276-282
Polymyxin B in micromolar concentrations induces current fluctuations in li
quid crystalline bilayer lipid membranes from dipalmitoylphosphatidic acid
identified as ion channels. The appearance of ion channels correlates with
phase separation of the lipid in the presence of peptide polycations detect
ed by differential scanning calorimetry. Ca2+ also induces the formation of
ion channels in liquid crystalline bilayer lipid membranes from dipalmitoy
lphosphatidic acid followed by the phase transition of the phospholipid. Th
e capacitive current, which indicates the possibility of structural transfo
rmations of bilayer - non-bilayer type (hexagonal phase II), precedes the f
ormation of Ca2+-induced channels in bilayer lipid membranes from dipalmito
ylphosphatidic acid.