Skip to main content
SpringerLink
Log in

Asymmetry of the gramicidin channel in bilayers of asymmetric lipid composition: II. Voltage dependence of dimerization

  • Published:
The Journal of Membrane Biology Aims and scope Submit manuscript

Summary

The asymmetric current-voltage relationship of gramicidin-doped asymmetric bilayers made by the Montal-Mueller technique was investigated in current relaxation experiments. It was shown that, in addition to the contribution of the asymmetric single channel conductance to the asymmetry of the steady-state current-voltage relationship, there is an asymmetric voltage dependence of the step which leads to the formation of the conducting channel. This asymmetric voltage dependence could be simulated in a model assuming a membrane-internal electrical potential drop or an equivalent potential, called asymmetry potential, which could be compensated by externally applying an offset potential. Significant asymmetry potentials were found in asymmetric bilayers made of charged lipids or only of neutral lipids. The asymmetry potential, was dependent on the salt composition in the aqueous phase.

The factors responsible for the asymmetry potential do not appear to be of electrostatic origin. Several lines of evidence suggest that the dimerization step which leads to the conducting ion channel may be a complex series of reactions which are influenced by one or more membrane structural properties not yet characterized, in addition to the effects of the externally applied electric field.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Alvarez, O., Latorre, R. 1978. Voltage-dependent capacitance in lipid bilayers made from monolayers.Biophys. J. 21:1

    Google Scholar 

  • Anderson, O.S., Finkelstein, A., Katz, I., Cass, A. 1976. The effect of phloretin on the permeability of thin lipid membranes.J. Gen. Physiol. 67:749

    Google Scholar 

  • Apell, H.J., Bamberg, E., Alpes, H., Läuger, P. 1977. Formation of ion channels by a negatively charged anlaog of gramicidin A.J. Membrane Biol. 31:171

    Google Scholar 

  • Bamberg, E., Apell, H.-J., Alpes, H. 1977. Structure of the gramicidin A channel: Discrimination between theπ L,D and the β helix by electrical measurements with lipid bilayer membranes.Proc. Nat. Acad. Sci. USA 74:2404

    Google Scholar 

  • Bamberg, E., Benz, R. 1976. Voltage-induced thickness changes of lipid bilayer membranes and the effect of an electrical field on gramicidin channel formation.Biochim. Biophys. Acta 426:570

    Google Scholar 

  • Bamberg, E., Läuger, P. 1973. Channel formation kinetics of gramicidin A in lipid bilayer membranes.J. Membrane Biol. 11:177

    Google Scholar 

  • Benz, R., Fröhlich, O., Läuger, P., Montal, M. 1975. Electrical capacity of black lipid films and of lipid bilayers made from monolayers.Biochim. Biophys. Acta 394:323

    Google Scholar 

  • Bradley, R.J., Urry, D.W., Okamoto, K., Rapaka, R. 1978. Channel structures of gramicidin. Characterization of succinyl derivatives.Science 200:435

    Google Scholar 

  • Fröhlich, O. 1979. Asymmetry of the gramicidin channel in bilayers of asymmetric lipid distribution. I. Single channel conductance.J. Membrane Biol. 48:365

    Google Scholar 

  • Hladky, S.B., Haydon, D.A. 1973. Membrane conductance and surface potential.Biochim. Biophys. Acta 318:464

    Google Scholar 

  • Hladky, S.B., Urban, B.W., Haydon, D.A. 1978. Ion movements in pores formed by gramicidin A.In: Membrane Transport Processes, Vol. 3. C. Stevens, R. Tsien, W. Chandler, editors. Raven Press, New York

    Google Scholar 

  • Kolb, H.-A., Bamberg, E. 1977. Influence of membrane thickness and ion concentration on the properties of the gramicidin A channel. Autocorrelation, spectral power density, relaxation and single channel studies.Biochim. Biophys. Acta 464:127

    Google Scholar 

  • Latorre, R., Hall, J.E. 1976. Dipole potential measurements in asymmetric membranes.Nature (London) 264:361

    Google Scholar 

  • Levitt, D.G. 1978. Electrostatic calculations for an ion channel. II. Kinetic behavior of the gramicidin A channel.Biophys. J. 22:221

    Google Scholar 

  • Montal, M., Mueller, P. 1972. Formation of bimolecular membranes, from monolayers and a study of their electrical properties.Proc. Nat. Acad. Sci. USA 69:3561

    Google Scholar 

  • Neher, E., Eibl, H. 1977. The influence of phospholipid polar groups on gramicidin channels.Biochim., Biophys. Acta 464:37

    Google Scholar 

  • Paltauf, F., Hauser, H., Phillips, M.C. 1971. Monolayer characteristics of some 1,2-diacyl, 1-alkyl-2-acyl and 1,2-dialkyl phosphlipids at the air-water interface.Biochim. Biophys. Acta 249:539

    Google Scholar 

  • Requena, J., Haydon, D.A., Hladky, S.B. 1975. Lenses and the compression of black lipid membranes by an electric field.Biophys. J. 15:77

    Google Scholar 

  • Szabo, G. 1975. Dual mechanism for the action of cholesterol on membrane permeability.Nature (London) 252:47

    Google Scholar 

  • Tosteson, D.C., Andreoli, T.E., Tieffenberg, M., Cook, P. 1968. The effects of macrocyclic compounds on cation transport in sheep red cells and thin and thick lipid membranes.J. Gen. Physiol. 51:373s

    Google Scholar 

  • Urry, D.W. 1971. The gramicidin A transmembrane channel: A proposedπ L,D helix.Proc. Nat. Acad. Sci. USA 68:672

    Google Scholar 

  • Urry, D.W. 1972. A molecular theory of ion-conducting channels: A field-dependent transition between conducting and nonconducting conformations.Proc. Nat. Acad. Sci. USA 69:1610

    Google Scholar 

  • Urry, D.W., Glickson, J.D., Mayers, D.F., Haider, J. 1972. Spectroscopic studies on the conformation of gramicidin A. Evidence for a new helical conformation.Biochemistry 11:487

    Google Scholar 

  • Urry, D.W., Goodall, M.C., Glickson, J.D., Mayers, D.F. 1971. The gramicidin A transmembrane channel: Characteristics of head-to-head dimerizedπ L,D, helices.Proc. Nat. Acad. Sci. USA 68:1901

    Google Scholar 

  • Urry, D.W., Long, M.M., Jacobs, M., Harris, R.D. 1975. Conformation and molecular mechanisms of carriers and channels.Ann. N.Y. Acad. Sci. 264:203

    Google Scholar 

  • Veatch, W.R., Blout, E.R. 1974. The aggregation of gramicidin A in solution.Biochemistry 13:5257

    Google Scholar 

  • Veatch, W.R., Fossel, R.T., Blout, E.R. 1974. The conformation of gramicidin A.Biochemistry 13:5249

    Google Scholar 

  • Veatch, W.R., Mathies, R., Eisenberg, M., Stryer, L. 1975. Simultaneous fluorescence and conductance studies of planar bilayer membranes containing a highly active and fluorescent analog of gramicidin A.J. Mol. Biol. 99:75

    Google Scholar 

Download references

Author information

Author notes

  1. O. Fröhlich

    Present address: Department of Pharmacological and Physiological Sciences, University of Chicago, 60637, Chicago, Illinois

Authors and Affiliations

  1. Fachbereich Biologie, University of Konstanz, D-7750, Konstanz, Germany

    O. Fröhlich

Authors
  1. O. Fröhlich
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Fröhlich, O. Asymmetry of the gramicidin channel in bilayers of asymmetric lipid composition: II. Voltage dependence of dimerization. J. Membrain Biol. 48, 385–401 (1979). https://doi.org/10.1007/BF01869448

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01869448

Keywords

Search

Navigation