title: Communication: Alamethicin can capture lipid-like molecules in the membrane.
abstract: Alamethicin (Alm) is a 19-mer antimicrobial peptide produced by fungus Trichoderma viride. Above a threshold concentration, Alm forms pores across the membrane, providing a mechanism of its antimicrobial action. Here we show that at a small concentration which is below the threshold value, Alm participates in formation of nanoscale lipid-mediated clusters of guest lipid-like molecules in the membrane. These results are obtained by electron spin echo (ESE) technique-a pulsed version of electron paramagnetic resonance-on spin-labeled stearic acid in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer with Alm added at 1/200 peptide-to-lipid ratio. ESE decay measurements are interpreted assuming that stearic acid molecules in the membrane are assembling around the Alm molecule. One may suggest that this Alm capturing effect on the guest lipid-like molecules could be important for the peptide antimicrobial action.
authors.affiliation: Voevodsky Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, 630090 Novosibirsk, Russia and Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia.
authors.forename: Ekaterina F
authors.initials: EF
authors.lastname: Afanasyeva
authors.affiliation: Voevodsky Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, 630090 Novosibirsk, Russia and Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia.
authors.forename: Victoria N
authors.initials: VN
authors.lastname: Syryamina
authors.affiliation: Voevodsky Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, 630090 Novosibirsk, Russia and Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia.
authors.forename: Sergei A
authors.initials: SA
authors.lastname: Dzuba
mesh_terms: D000408:Alamethicin / Q000737:chemistry / Q000494:pharmacology*; D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature
chemical_list: D010713:Phosphatidylcholines; D000408:Alamethicin; C028694:1-palmitoyl-2-oleoylphosphatidylcholine