The Journal of Membrane Biology

, Volume 14, Issue 1, pp 143–176 | Cite as

The nature of the voltage-dependent conductance induced by alamethicin in black lipid membranes

  • Moisés Eisenberg
  • James E. Hall
  • C. A. Mead


Alamethicin induces a conductance in black lipid films which increases exponentially with voltage. At low conductance the increase occurs in discrete steps which form a pattern of five levels, the second and third being most likely. The conductance of each level is directly proportional to salt concentration, inversely proportional to solution viscosity, and nearly independent of voltage.

The probability distribution of the five steps is not a function of voltage, but as the voltage is increased, more levels begin to appear. These can be explained as super-positions of the original five, both in position and relative probability.

This suggests that the five levels are associated with a physical entity which we call a pore. This point of view is confirmed by the following measurements. The kinetic response of the current to a voltage step is first order, and shows an exponential increase in rate of pore formation and an exponential decrease in rate of pore disappearance with voltage. If these rates are statistical, the number of pores should fluctuate about a voltage-dependent mean. High conductance current fluctuations are too large to be explained by fluctuation in the number of pores alone. But if fluctuations among the five levels are included, the magnitude of the fluctuations at high conductance is accurately predicted.

Alamethicin adsorbs reversibly to the membrane surface, and the conductance at a fixed voltage depends on the ninth power of alamethicin concentration and on the fourth power of salt concentration, in the aqueous phase. In our bacterial phosphatidyl ethanolamine membranes, alamethicin added to one side of the membrane produces elevated conductance only when the voltage on that side is increased.


Salt Concentration High Conductance Ethanolamine Phosphatidyl Ethanolamine Solution Viscosity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. Bamberg, G., Laüger, P. 1973. Channel formation kinetics of gramicidin A in lipid bilayer membranes.J. Membrane Biol. 11:177Google Scholar
  2. Bean, R. C., Shepherd, W. C., Chan, H., Eichner, J. 1969. Discrete conductance fluctuations in lipid bilayer protein membranes.J. Gen. Physiol. 53:741PubMedGoogle Scholar
  3. Boheim, G. H. 1972. Erregbarkeit Schwarzer Lipid-Membranen. Thesis RWTH, Aachen, GermanyGoogle Scholar
  4. Cherry, R. J., Chapman, D., Graham, D. E. 1972. Studies of the conductance changes induced in bimolecular lipid membranes by alamethicin.J. Membrane Biol. 7:325Google Scholar
  5. Ehrenstein, G., Lecar, H., Nossal, R. 1970. The nature of the negative resistance in bimolecular lipid membranes containing excitability inducing material.J. Gen. Physiol. 55:119PubMedGoogle Scholar
  6. Eisenberg, M. 1972. Voltage Gateable Ionic Pores in Black Lipid Membranes Induced by Alamethicin. Ph.D. Thesis. California Institute of Technology, Pasadena, CaliforniaGoogle Scholar
  7. Gordon, L. G. M., Haydon, D. A. 1972. The unit conductance channel of alamethicin.Biochim. Biophys. Acta 255:1014PubMedGoogle Scholar
  8. Hauser, H., Finer, E. G., Chapman, D. 1970. Nuclear magnetic resonance studies of the polypeptide alamethicin and its interaction with phospholipids.J. Mol. Biol. 53:4AGoogle Scholar
  9. Hille, B. 1970. Ionic channels in nerve membranes.In: Progress in Biophysics and Molecular Biology. J. A. V. Butler, Editor. Vol. 21, p. 1. Pergamon Press, Oxford and New YorkGoogle Scholar
  10. Hladky, S. B., Haydon, D. A. 1972. Ion transfer across lipid membranes in the presence of gramicidin A. I. Studies of the unit conductance channel.Biochim. Biophys. Acta 274:294PubMedGoogle Scholar
  11. Hodgkin, A. L., Huxley, A. F. 1952. Quantitative description of membrane current and its application to conduction and excitation in nerve.J. Physiol. 117:550Google Scholar
  12. Huebner, J., Bruner, L. J. 1972. Apparatus for measurements of the dynamic current-voltage characteristics of membranes.J. Phys. E. Sci. Instrum. 5:310Google Scholar
  13. Johnson, M. 1973. Structure and Function of Alamethicin. Ph.D. Thesis. Northwestern University, Evanston, IllinoisGoogle Scholar
  14. Lüttgau, H.-C. 1958. Sprunghafte Schwankungen unterschwelliger Potentiale an markhaltigen Nervenfasern.Z. Naturf. 13b:692Google Scholar
  15. Mauro, A., Nanavati, R. P., Heyer, E. 1972. Time-variant conductance of bilayer membranes treated with monoazomycin and alamethicin.Proc. Nat. Acad. Sci. 69:3742PubMedGoogle Scholar
  16. McMullen, A. I., Marlborough, D. I., Bayley, P. M. 1971. The conformation of alamethicin.F.E.B.S. 16:278Google Scholar
  17. McMullen, A. I., Stirrup, J. A. 1971. The aggregation of alamethicin.Biochim. Biophys. Acta 241:807PubMedGoogle Scholar
  18. Mueller, P., Rudin, D. O. 1968. Action potentials induced in bimolecular lipid membranes.Nature 217:713PubMedGoogle Scholar
  19. Mueller, P., Rudin, D. O., Tien, H. T., Wescot, W. C. 1962. Reconstitution of cell membrane structurein vitro and its transformation into an excitable system.Nature 194:979PubMedGoogle Scholar
  20. Muller, R. U., Finkelstein, A. 1972. Voltage-dependant conductance induced in thin lipid films by monazomycin.J. Gen. Physiol. 60:263PubMedGoogle Scholar
  21. Payne, J. W., Jakes, R., Hartley, B. S. 1970. The primary structure of alamethicin.Biochem. J. 117:757PubMedGoogle Scholar
  22. Pressman, B. C. 1968. Ionophorous antibiotics as models for biological transport.Fed. Proc. 27:1283PubMedGoogle Scholar
  23. Sheetz, M. P., Chan, S. I. 1972. Effect of sonication on the structure of lecithin bilayers.Biochemistry 11:4573PubMedGoogle Scholar

Copyright information

© Springer-Verlag New York Inc. 1973

Authors and Affiliations

  • Moisés Eisenberg
    • 1
  • James E. Hall
    • 1
  • C. A. Mead
    • 1
  1. 1.Division of Biology and Department of Electrical EngineeringCalifornia Institute of TechnologyPasadena

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