Electrical properties of bimolecular phospholipid membranes

Läuger, P.; Lesslauer, Werner; Marti, E.; Richter, J.

doi:10.1016/0005-2736(67)90004-1

Cited by 228 publications

(70 citation statements)

References 25 publications

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“…I-could enter the cell via passive diffusion through the cell membrane (Liuger, Lesslauer, Marti & Richter, 1967;Finkelstein & Cass, 1968), as it combines with 12 to form lipid soluble complexes such as I3-and Ij-. This mechanism requires the presence of 12, but traces of this compound were most probably present in the experiments, in sufficient amount to induce I-entry (Finkelstein & Cass, 1968).…”

Section: Ion Substitution Experimentsmentioning

confidence: 99%

Calcium‐dependent chloride currents in isolated cells from rat lacrimal glands.

Evans¹,

Marty²

1986

The Journal of Physiology

245

140

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Section: Ion Substitution Experimentsmentioning

confidence: 99%

Calcium‐dependent chloride currents in isolated cells from rat lacrimal glands.

Evans¹,

Marty²

1986

The Journal of Physiology

245

140

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“…Closely related equations may be found in previous treatments of planar membranes (Läuger et al 1967;Everitt & Haydon, 1968 ;Walz et al 1969). The PB-V Eq.…”

Section: The Transmembrane Potential and The Pb-v Equationmentioning

confidence: 99%

Theoretical and computational models of biological ion channels

Roux

Allen

Bernèche

et al. 2004

Quart. Rev. Biophys.

383

419

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Abstract. The goal of this review is to establish a broad and rigorous theoretical framework to describe ion permeation through biological channels. This framework is developed in the context of atomic models on the basis of the statistical mechanical projection-operator formalism of Mori and Zwanzig. The review is divided into two main parts. The first part introduces the fundamental concepts needed to construct a hierarchy of dynamical models at different level of approximation. In particular, the potential of mean force (PMF) as a configuration-dependent free energy is introduced, and its significance concerning equilibrium and non-equilibrium phenomena is discussed. In addition, fundamental aspects of membrane electrostatics, with a particular emphasis on the influence of the transmembrane potential, as well as important computational techniques for extracting essential information from all-atom molecular dynamics (MD) simulations are described and discussed. The first part of the review provides a theoretical formalism to 'translate ' the information from the atomic structure into the familiar language of phenomenological models of ion permeation. The second part is aimed at reviewing and contrasting results obtained in recent computational studies of three very different channels : the gramicidin A (gA) channel, which is a narrow one-ion pore (at moderate concentration), the KcsA channel from Streptomyces lividans, which is a narrow multi-ion pore, and the outer membrane matrix porin F (OmpF) from Escherichia coli, which is a trimer of three b-barrel subunits each forming wide aqueous multi-ion pores. Comparison with experiments demonstrates that current computational models are approaching semi-quantitative accuracy and are able to provide significant insight into the microscopic mechanisms of ion conduction and selectivity. We conclude that all-atom MD with explicit water molecules can represent important structural features of complex biological channels accurately, including such features as the location of ion-binding sites along the permeation pathway. We finally discuss the broader issue of the validity of ion permeation models and an outlook to the future.

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“…O-Pyrornellitylgramicidin was prepared as described before (17). Optically black lipid membranes were formed in the usual way from a 1 to 2% (wt/vol) lipid solution in n-decane in a thermostated Teflon cell filled with electrolyte solution (20 (19). The homogeneity and the molecular weight were checked by sedimentation analysis on an ultracentrifuge (Beckman ultracentrifuge type E).…”

Section: Methodsmentioning

confidence: 99%

Structure of the gramicidin A channel: Discrimination between the π _L,D and the β helix by electrical measurements with lipid bilayer membranes

Bamberg

Apell

Alpes

1977

Proc. Natl. Acad. Sci. U.S.A.

129

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Measurements with different chemically modified gramicidins in lipid bilayer membranes were used to discriminate between the dimneric rLD helix proposed by Urry and the dimeric parallel or antiparallel helices proposed by Veatch and Blout. Evidence for the 7rLD helix was obtained on the basis of the different actions of a negatively charged 0-pyromellitylgramicidin and a negatively charged N-pyromellityldesformylgramicidin on lipid bilayer membranes. O-Pyromellitylgramicidin forms ionic channels in lipid membranes when it is applied to both sides of the membrane. In contrast to unmodified gramicidin, O-pyromellitylgramicidin is inactive when it is applied only to one side of the membrane. N-Pyromellityldesformylgramicidin does not form ionic channels in lipid bilayer membranes whether it is applied to one or both sides of the membrane. These results support the view that the gramicidin channel is formed by two 7rLD helices. Dimer formation by head-to-head association of two 7rL D helices needs six intermolecular hydrogen bonds, which are located at the formyl end of the molecule and which occur deep within the lipid membrane. In the head-to-head associated 7rL,D helix the absence of the formyl group leads to an inactivation of the e tide, whereas in a parallel or antiparallel double-stranded Eefix the absence of the formyl group should have only minor effects.Gramicidin A is a linear pentadecapeptide consisting of 15 hydrophobic alternating D,L-amina acids. It induces, in natural membranes and artificial lipid membranes, a high permeability for small monovalent cations. There is strong evidence that the peptide forms pore-like channels (1-12). For the structure of the channel two proposals exist. One possibility is a head-to-head association (formyl end to forrnyl end) of two helical monomers, where the helix of the monomer is a 7rLD-helix (7, 13). The helix in the dimeric form is stabilized by 22 intramolecular and 6 intermolecular hydrogen bonds. Urry et al. (7) proposed four types of 7rL,D helices, where the xr6 Dhelix seems to be the most probable. With the length of that dimer (30 A) and the diameter of the hydrophilic hole (4 A), the best geometrical dimensions are obtained to explain the results gotten in the membrane experiments. The other possible lXL,D helices either are too short (r8,D and lrLD helices) to form a transmembrane channel or the pore size is too small (1.8 A diameter for -rD L helix).An alternate model, a double-stranded helix, in which both peptide chains are coiled. around a common axis, has been proposed by Veatch et al. (14,15). In contrast to the 7rL,D helices, these helices have no intramolecular hydrogen bonds but 20-28 intermolecular hydrogen bonds (14). A common feature of both models is the existence of a narrow pore along the axis of the dimer that is lined with oxygen atoms of the peptide carbonyls. The essential difference between both models is that the lrLD helices dimerize when the formyl group is intact so that the intermolecular hydrogen bonds can form a bridg...

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Electrical properties of bimolecular phospholipid membranes

Cited by 228 publications

References 25 publications

Calcium‐dependent chloride currents in isolated cells from rat lacrimal glands.

Calcium‐dependent chloride currents in isolated cells from rat lacrimal glands.

Theoretical and computational models of biological ion channels

Structure of the gramicidin A channel: Discrimination between the π _L,D and the β helix by electrical measurements with lipid bilayer membranes

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Electrical properties of bimolecular phospholipid membranes

Cited by 228 publications

References 25 publications

Calcium‐dependent chloride currents in isolated cells from rat lacrimal glands.

Calcium‐dependent chloride currents in isolated cells from rat lacrimal glands.

Theoretical and computational models of biological ion channels

Structure of the gramicidin A channel: Discrimination between the π L,D and the β helix by electrical measurements with lipid bilayer membranes

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Product

Resources

About

Structure of the gramicidin A channel: Discrimination between the π _L,D and the β helix by electrical measurements with lipid bilayer membranes