Polymyxin B and Ca (2+) induce conductance fluctuations in the dipalmitoyl phosphatidic acid bilayer lipid membrane
Korepanova, E.A.; Shevchenko, E.V.; Kozhomkulov, E.T.; Vasserman, A.N.; Morozova, E.R.; Antonov, V.F.
Biofizika 45(2): 276-282
2000
ISSN/ISBN: 0006-3029 PMID: 10776540 Document Number: 522517
Polymyxin B in micromolar concentrations induces current fluctuations in liquid 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 detected by differential scanning calorimetry. Ca2+ also induces the formation of ion channels in liquid crystalline bilayer lipid membranes from dipalmitoylphosphatidic acid followed by the phase transition of the phospholipid. The capacitive current, which indicates the possibility of structural transformations of bilayer-non-bilayer type (hexagonal phase II), precedes the formation of Ca(2+)-induced channels in bilayer lipid membranes from dipalmitoylphosphatidic acid.