title: Probing membrane permeabilization by the antibiotic lipopeptaibol trichogin GA IV in a tethered bilayer lipid membrane.
abstract: The lipopeptaibol trichogin GA IV (TCG) can be incorporated in the lipid bilayer moiety of a mercury-supported tethered bilayer lipid membrane (tBLM) at a non-physiological transmembrane potential of about -240 mV, negative on the trans side of the bilayer. Once incorporated in the tBLM, TCG is stable over the range of physiological transmembrane potentials and permeabilizes the membrane at transmembrane potentials negative of -80 / -90 mV. The chronocoulometric behavior is consistent with a kinetics of nucleation and growth of bundles of TCG building blocks with ion-channel properties. The TCG building blocks also permeabilize the lipid bilayer, albeit at more negative transmembrane potentials, and can be tentatively regarded as dimers of aligned TCG helical monomers. The cyclic voltammograms of tBLMs incorporating TCG point to a voltage-gated behavior of the TCG channel, similar to that exhibited by the peptaibol alamethicin.
authors.affiliation: Department of Chemistry, Florence University, Via della Lastruccia 3, 50019 Sesto Fiorentino (Firenze), Italy. lucia.becucci@unifi.it
authors.forename: Lucia
authors.initials: L
authors.lastname: Becucci
authors.forename: Flavio
authors.initials: F
authors.lastname: Maran
authors.forename: Rolando
authors.initials: R
authors.lastname: Guidelli
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D002462:Cell Membrane / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology; D002463:Cell Membrane Permeability / Q000187:drug effects; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques; D007476:Ionophores / Q000737:chemistry / Q000494:pharmacology; D008051:Lipid Bilayers / Q000737:chemistry*; D055666:Lipopeptides / Q000737:chemistry* / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D008956:Models, Chemical; D008958:Models, Molecular; D010743:Phospholipids / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D007476:Ionophores; D008051:Lipid Bilayers; D055666:Lipopeptides; D010743:Phospholipids; C116419:trichogin GA IV