Molecular origin of the cation selectivity in OmpF porin: single channel conductances vs. free energy calculation

Danelon, Christophe; Suenaga, Atsushi; Winterhalter, Mathias; Yamato, Ichiro

doi:10.1016/s0301-4622(03)00062-0

Cited by 88 publications

(122 citation statements)

References 57 publications

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“…Differences in the conductance of each monomer closure have also been observed for OmpF. 28 Inactivation of OmpT is also much faster (note the different scale bars for Fig. 1C and F) and occurs at lower voltages than for OmpU, because of different voltage sensitivities, as documented.…”

Section: Behavior Of Ompu and Ompt At Neutral Phsupporting

confidence: 59%

“…16,28,29 It is a hallmark of porin behavior that this inactivation takes place in three distinct steps, believed to correspond to the successive closures of each monomer. 28 The trace of panel C shows that OmpU indeed displays three major closed steps (indicated by tick marks) which may correspond to each monomer, but additional levels of smaller or larger amplitudes are also observed. This is not an idiosyncrasy of patch-clamp, as similar behaviors are observed in planar lipid bilayers as well.…”

Section: Behavior Of Ompu and Ompt At Neutral Phmentioning

confidence: 99%

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Modulation ofVibrio choleraePorin Function by Acidic pH

Duret¹,

Simonet²,

Delcour³

2007

Channels

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Section: Behavior Of Ompu and Ompt At Neutral Phsupporting

confidence: 59%

Section: Behavior Of Ompu and Ompt At Neutral Phmentioning

confidence: 99%

Modulation ofVibrio choleraePorin Function by Acidic pH

Duret¹,

Simonet²,

Delcour³

2007

Channels

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“…Figures 3 and 4 show that the measurements made with the silicon device were very similar to that of the commercial bilayer cup. The average conductance of a single channel (measured from the size of the step current) was ∼0.7 nS which is very similar to other measurements of OmpF porin channels in 0.5M KCl solution [23,24].…”

Section: Resultssupporting

confidence: 86%

Ion Channels on Silicon

Wilk

Petrossian

Goryll

et al. 2005

e-J. Surf. Sci. Nanotechnol.

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We present results showing that silicon substrates can be used as a universal platform for recording the electrical activity of ion channels inserted into suspended bilayer membranes. The bilayers span 150 µm apertures etched into silicon substrates using standard microelectronics processing techniques. The silicon is oxidized, patterned with a 75 µm thick SU-8 epoxy resist and then coated with a thin layer of polytetrafluoroethylene rendering the surface hydrophobic. Reversible Ag/AgCl electrodes are integrated around the circumference of the opening and provide long-term stable measurements of the ion channel currents. Characteristic measurements of OmpF porin ion channel protein in phospholipid bilayers and α-hemolysin toxin protein in triblock copolymer layers were made. Long-term measurements showed that ion channel activity could be recorded 22 hours after initial formation of a lipid bilayer.

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“…This value is approximately 2 times larger than the ∼1.2 nS conductance experimentally found. A similar restriction on passive ionic transport at high salt concentration has been observed in large water-filled biological channels 28 and in solid-state nanopores 29 and is attributed to surface charge effects. Although the exact thickness of silicon oxide deposited on the back side of the membrane is not known, the result is valid for any reasonable values of the channel length.…”

Section: Resultssupporting

confidence: 65%

Fabrication and Functionalization of Nanochannels by Electron-Beam-Induced Silicon Oxide Deposition

et al. 2006

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We report on the fabrication and electrical characterization of functionalized solid-state nanopores in low stress silicon nitride membranes. First, a pore of ∼50 nm diameter was drilled using a focused ion beam technique, followed by the local deposition of silicon dioxide. A low-energy electron beam induced the decomposition of adsorbed tetraethyl orthosilicate resulting in site-selective functionalization of the nanopore by the formation of highly insulating silicon oxide. The deposition occurs monolayer by monolayer, which allows for control of the final diameter with subnanometer accuracy. Changes in the pore diameter could be monitored in real time by scanning electron microscopy. Recorded ion currents flowing through a single nanopore revealed asymmetry in the ion conduction properties with the sign of the applied potential. The low-frequency excess noise observed at negative voltage originated from stepwise conductance fluctuations of the open pore.

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Molecular origin of the cation selectivity in OmpF porin: single channel conductances vs. free energy calculation

Cited by 88 publications

References 57 publications

Modulation ofVibrio choleraePorin Function by Acidic pH

Modulation ofVibrio choleraePorin Function by Acidic pH

Ion Channels on Silicon

Fabrication and Functionalization of Nanochannels by Electron-Beam-Induced Silicon Oxide Deposition

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