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Electrophysiology Investigation of Trichogin GA IV Activity in Planar Lipid Membranes Reveals Ion Channels of Well‐Defined Size
Author(s) -
Iftemi Sorana,
De Zotti Marta,
Formaggio Fernando,
Toniolo Claudio,
Stella Lorenzo,
Luchian Tudor
Publication year - 2014
Publication title -
chemistry and biodiversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 70
eISSN - 1612-1880
pISSN - 1612-1872
DOI - 10.1002/cbdv.201300334
Subject(s) - alamethicin , chemistry , ion channel , electrophysiology , biophysics , membrane , lipid bilayer , bilayer , transmembrane channels , membrane biophysics , membrane potential , voltage gated ion channel , biochemistry , biology , neuroscience , receptor
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.