title: Electrophysiology investigation of Trichogin GA IV activity in planar lipid membranes reveals ion channels of well-defined size.
abstract: Trichogin GA IV, an antimicrobial peptaibol, exerts its function by augmenting membrane permeability, but the molecular aspects of its pore-forming mechanism are still debated. Several lines of evidence indicate a 'barrel-stave' channel structure, similar to that of alamethicin, but the length of a trichogin helix is too short to span a normal bilayer. Herein, we present electrophysiology measurements in planar bilayers, showing that trichogin does form channels of a well-defined size (R=4.2⋅10(9)  Ω; corresponding at least to a trimeric aggregate) that span the membrane and allow ion diffusion, but do not exhibit voltage-dependent rectification, unlike those of alamethicin.
authors.affiliation: Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, 11, Blvd. Carol I, RO-700506 Iasi (phone: +40-232-201191).
authors.forename: Sorana
authors.initials: S
authors.lastname: Iftemi
authors.forename: Marta
authors.initials: M
authors.lastname: De Zotti
authors.forename: Fernando
authors.initials: F
authors.lastname: Formaggio
authors.forename: Claudio
authors.initials: C
authors.lastname: Toniolo
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Stella
authors.forename: Tudor
authors.initials: T
authors.lastname: Luchian
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004058:Diffusion / Q000187:drug effects; D004594:Electrophysiology; D007473:Ion Channels / Q000378:metabolism*; D007476:Ionophores / Q000494:pharmacology*; D007477:Ions / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism*; D055666:Lipopeptides / Q000494:pharmacology*; D010539:Permeability / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D007473:Ion Channels; D007476:Ionophores; D007477:Ions; D008051:Lipid Bilayers; D055666:Lipopeptides; C116419:trichogin GA IV
keywords: Antimicrobial peptides; Electrophysiology; Lipid membranes; Peptaibols; Peptides; Trichogin GA IV