Channel-forming activity of syringomycin E in two mercury-supported biomimetic membranes

Lucia Becucci, Vania Tramonti, Alberto Fiore, Vincenzo Fogliano, Andrea Scanloni, Rolando Guidelli

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The lipodepsipeptide syringomycin E (SR-E) interacts with two mercury-supported biomimetic membranes, which consist of a self-assembled phospholipid monolayer (SAM) and of a tethered bilayer lipid membrane (tBLM) separated from the mercury surface by a hydrophilic tetraethyleneoxy (TEO) spacer that acts as an ionic reservoir. SR-E interacts more rapidly and effectively with a SAM of dioleoylphosphatidylserine (DOPS) than with one of dioleoylphosphatidylcholine (DOPC). The proximal lipid monolayer of the tBLM has no polar head region, being linked to the TEO spacer via an ether bond, while the distal monolayer consists of either a DOPC or a DOPS leaflet. The ion flow into or out of the spacer through the lipid bilayer moiety of the tBLM was monitored by potential step chronocoulometry and cyclic voltammetry. With the distal monolayer bathed by aqueous 0.1 M KCl and 0.8 μM SR-E, an ion flow in two stages was monitored with DOPC at pH 3 and 5.4 and with DOPS at pH 3, while a single stage was observed with DOPS at pH 5.4. This behavior was compared with that already described at conventional bilayer lipid membranes. The sigmoidal shape of the chronocoulometric charge transients points to an aggregation of SR-E monomers forming an ion channel via a mechanism of nucleation and growth. The ion flow is mainly determined by potassium ions, and is inhibited by calcium ions. The contribution to the transmembrane potential from the distal leaflet depends more on the nature of the lipid than that of the ion channel.
Original languageEnglish
Pages (from-to)932–941
Number of pages10
JournalBBA Biomembranes
Volume1848
Issue number4
Early online date29 Dec 2014
DOIs
Publication statusPublished - Apr 2015

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Lipid bilayers
Biomimetics
Mercury
Monolayers
Membrane Lipids
Ions
Membranes
Ion Channels
Phospholipids
Lipids
Ether
Cyclic voltammetry
Potassium
Nucleation
Agglomeration
Monomers
syringomycin E
Calcium
1,2-oleoylphosphatidylcholine

Cite this

Becucci, Lucia ; Tramonti, Vania ; Fiore, Alberto ; Fogliano, Vincenzo ; Scanloni, Andrea ; Guidelli, Rolando. / Channel-forming activity of syringomycin E in two mercury-supported biomimetic membranes. In: BBA Biomembranes. 2015 ; Vol. 1848, No. 4. pp. 932–941.
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abstract = "The lipodepsipeptide syringomycin E (SR-E) interacts with two mercury-supported biomimetic membranes, which consist of a self-assembled phospholipid monolayer (SAM) and of a tethered bilayer lipid membrane (tBLM) separated from the mercury surface by a hydrophilic tetraethyleneoxy (TEO) spacer that acts as an ionic reservoir. SR-E interacts more rapidly and effectively with a SAM of dioleoylphosphatidylserine (DOPS) than with one of dioleoylphosphatidylcholine (DOPC). The proximal lipid monolayer of the tBLM has no polar head region, being linked to the TEO spacer via an ether bond, while the distal monolayer consists of either a DOPC or a DOPS leaflet. The ion flow into or out of the spacer through the lipid bilayer moiety of the tBLM was monitored by potential step chronocoulometry and cyclic voltammetry. With the distal monolayer bathed by aqueous 0.1 M KCl and 0.8 μM SR-E, an ion flow in two stages was monitored with DOPC at pH 3 and 5.4 and with DOPS at pH 3, while a single stage was observed with DOPS at pH 5.4. This behavior was compared with that already described at conventional bilayer lipid membranes. The sigmoidal shape of the chronocoulometric charge transients points to an aggregation of SR-E monomers forming an ion channel via a mechanism of nucleation and growth. The ion flow is mainly determined by potassium ions, and is inhibited by calcium ions. The contribution to the transmembrane potential from the distal leaflet depends more on the nature of the lipid than that of the ion channel.",
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Becucci, L, Tramonti, V, Fiore, A, Fogliano, V, Scanloni, A & Guidelli, R 2015, 'Channel-forming activity of syringomycin E in two mercury-supported biomimetic membranes', BBA Biomembranes, vol. 1848, no. 4, pp. 932–941. https://doi.org/10.1016/j.bbamem.2014.12.007

Channel-forming activity of syringomycin E in two mercury-supported biomimetic membranes. / Becucci, Lucia; Tramonti, Vania; Fiore, Alberto; Fogliano, Vincenzo; Scanloni, Andrea; Guidelli, Rolando.

In: BBA Biomembranes, Vol. 1848, No. 4, 04.2015, p. 932–941.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Channel-forming activity of syringomycin E in two mercury-supported biomimetic membranes

AU - Becucci, Lucia

AU - Tramonti, Vania

AU - Fiore, Alberto

AU - Fogliano, Vincenzo

AU - Scanloni, Andrea

AU - Guidelli, Rolando

PY - 2015/4

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N2 - The lipodepsipeptide syringomycin E (SR-E) interacts with two mercury-supported biomimetic membranes, which consist of a self-assembled phospholipid monolayer (SAM) and of a tethered bilayer lipid membrane (tBLM) separated from the mercury surface by a hydrophilic tetraethyleneoxy (TEO) spacer that acts as an ionic reservoir. SR-E interacts more rapidly and effectively with a SAM of dioleoylphosphatidylserine (DOPS) than with one of dioleoylphosphatidylcholine (DOPC). The proximal lipid monolayer of the tBLM has no polar head region, being linked to the TEO spacer via an ether bond, while the distal monolayer consists of either a DOPC or a DOPS leaflet. The ion flow into or out of the spacer through the lipid bilayer moiety of the tBLM was monitored by potential step chronocoulometry and cyclic voltammetry. With the distal monolayer bathed by aqueous 0.1 M KCl and 0.8 μM SR-E, an ion flow in two stages was monitored with DOPC at pH 3 and 5.4 and with DOPS at pH 3, while a single stage was observed with DOPS at pH 5.4. This behavior was compared with that already described at conventional bilayer lipid membranes. The sigmoidal shape of the chronocoulometric charge transients points to an aggregation of SR-E monomers forming an ion channel via a mechanism of nucleation and growth. The ion flow is mainly determined by potassium ions, and is inhibited by calcium ions. The contribution to the transmembrane potential from the distal leaflet depends more on the nature of the lipid than that of the ion channel.

AB - The lipodepsipeptide syringomycin E (SR-E) interacts with two mercury-supported biomimetic membranes, which consist of a self-assembled phospholipid monolayer (SAM) and of a tethered bilayer lipid membrane (tBLM) separated from the mercury surface by a hydrophilic tetraethyleneoxy (TEO) spacer that acts as an ionic reservoir. SR-E interacts more rapidly and effectively with a SAM of dioleoylphosphatidylserine (DOPS) than with one of dioleoylphosphatidylcholine (DOPC). The proximal lipid monolayer of the tBLM has no polar head region, being linked to the TEO spacer via an ether bond, while the distal monolayer consists of either a DOPC or a DOPS leaflet. The ion flow into or out of the spacer through the lipid bilayer moiety of the tBLM was monitored by potential step chronocoulometry and cyclic voltammetry. With the distal monolayer bathed by aqueous 0.1 M KCl and 0.8 μM SR-E, an ion flow in two stages was monitored with DOPC at pH 3 and 5.4 and with DOPS at pH 3, while a single stage was observed with DOPS at pH 5.4. This behavior was compared with that already described at conventional bilayer lipid membranes. The sigmoidal shape of the chronocoulometric charge transients points to an aggregation of SR-E monomers forming an ion channel via a mechanism of nucleation and growth. The ion flow is mainly determined by potassium ions, and is inhibited by calcium ions. The contribution to the transmembrane potential from the distal leaflet depends more on the nature of the lipid than that of the ion channel.

U2 - 10.1016/j.bbamem.2014.12.007

DO - 10.1016/j.bbamem.2014.12.007

M3 - Article

VL - 1848

SP - 932

EP - 941

JO - Biochimica et Biophysica Acta - Biomembranes

JF - Biochimica et Biophysica Acta - Biomembranes

SN - 0005-2736

IS - 4

ER -