The Journal of Membrane Biology

, Volume 50, Issue 3–4, pp 271–285 | Cite as

Dicarboxylic acid analogs of Gramicidin A: Dimerization kinetics and single channel properties

  • H. -J. Apell
  • E. Bamberg
  • H. Alpes
Article

Summary

According to the model of Urry, the cation-permeable gramicidin channel is a dimeric helix formed by association of two peptide monomers linked at their amino ends. In this paper the channel properties of gramicidin analogs are described which have been obtained by chemical modification at the coupling site of the two half-channels. In these analogs the amino terminal-CHO group is replaced by-CO(CH2) n COOH(n=2, 3, 4, 5, 6). All analogs form conducting channels in black lipid membranes with the same general properties as found for gramicidin A. The observation that the channel-forming activity decreases with increasing pH is consistent with the notion that the half-channels are linked at the amino terminus. The channel lifetime of the different analogs varies between 2 msec and ≧50 sec, the longest lifetime being found for the compound withn=3. The single-channel conductance Λ is always smaller than that of gramicidin A, but the reduction of Λ depends on the nature of the permeable ion. Ion specificity was studied at 1m electrolyte by measuring the conductance Λ for different permeable ions (Na+, K+, Cs+). The conductance ratioΛ(Cs+)/Λ(Na+) was found to vary between 2 and 10.5 for the different analogs.

Keywords

Dicarboxylic Acid Amino Terminus Gramicidin Acid Analog Longe Lifetime 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Apell, H.-J. 1978. Untersuchungen an Gramicidin und Gramicidinanalogen in künstlichen Membranen. Dissertationen, Universität KonstanzGoogle Scholar
  2. Apell, H.-J., Bamberg, E., Alpes, H., Läuger, P. 1977. Formation of ion channels by a negatively charged analog of gramicidin A.J. Membrane Biol. 31:171Google Scholar
  3. Bamberg, E., Apell, H.-J., Alpes, H. 1977. Structure of the gramicidin channel. Discrimination between the πL,D-helix and the β-helix by electrical measurements with lipid bilayer membranes.Proc. Nat. Acad. Sci. USA 74:2402Google Scholar
  4. Bamberg, E., Apell, H.-J., Alpes, H., Gross, E., Morell, J.E., Harbough, J.F., Janko, K., Läuger, P. 1978. Ion channels formed by chemical analogs of gramicidin AFed. Proc. 37:2623Google Scholar
  5. Bamberg, E., Alpes, H., Apell, H.-J., Bradley, R.J., Härter, B., Quelle, M.-J., Urry, D.W. 1979. Formation of ionic channels in black lipid membranes by succinic derivatives of gramicidin AJ.Membrane Biol. 50:257Google Scholar
  6. Bamberg, E., Benz, R., 1976. Voltage-induced thickness changes of lipid bilayer membranes and the effect of an electric field on gramicidin A channel formation.Biochim. Biophys. Acta 426:570Google Scholar
  7. Bamberg, E., Janko, K. 1977. The action of a carbonsuboxide dimerized gramicidin A on lipid bilayer membranes.Biochim. Biophys. Acta 465:486Google Scholar
  8. Bamberg, E., Läuger, P. 1973. Channel formation kinetics of gramicidin A in lipid bilayer membranes.J. Membrane Biol. 11:177Google Scholar
  9. Bamberg, E., Läuger, P. 1974. Temperature dependent properties of gramicidin A channels.Biochim. Biophys. Acta 419:223Google Scholar
  10. Bamberg, E., Läuger, P. 1977. Blocking of the gramicidin channel by divalent cations.J. Membrane Biol. 35:351Google Scholar
  11. Bamberg, E., Noda, K., Gross, E., Läuger, P. 1976. Single channel parameters of gramicidin A, B and C.Biochim. Biophys. Acta 419:223Google Scholar
  12. Bradley, R., Urry, D.W., Okamoto, K., Rapaka, R. 1978. Channel structures of gramicidin: Characterization of succinyl derivatives.Science 200:435Google Scholar
  13. Hladky, S.B., Haydon, D.A. 1972. Ion transfer across liquid membranes in presence of gramicidin A. Studies on the unit channel conductance.Biochim. Biophys. Acta 274:294Google Scholar
  14. Janko, K., Benz, R. 1977. Properties of lipid bilayer membranes made from lipids containing phytanic acid.Biochim. Biophys. Acta 470:8Google Scholar
  15. Kolb, H.-A., Läuger, P., Bamberg, E. 1975. Correlation analysis of electrical noise in lipid bilayer membranes: Kinetics of gramicidin A channels.J. Membrane Biol. 20:133Google Scholar
  16. Läuger, P. 1973. Ion transport through pores: A rate-theory analysis.Biochim. Biophys. Acta 311:423Google Scholar
  17. Läuger, P., Lesslauer, W., Marti, E., Richter, J. 1967. Electrical properties of bimolecular phospholipid membranes.Biochim. Biophys. Acta 135:20Google Scholar
  18. Morrison, J.D., Robertson, J.M. 1949. The crystal and molecular structure of certain dicarboxylic acids. VII. β-glutaric acid.J. Chem. Soc. 1949:1001Google Scholar
  19. Sauvé, R., Bamberg, E. 1978. 1/f noise in black lipid membranes induced by ionic channels formed by chemically dimerized gramicidin A.J. Membrane Biol. 43:317Google Scholar
  20. Szabo, G., Urry, D.W. 1979. N-Acetyl gramicidins: Single-channel properties and implications for channel structure.Science 203:55Google Scholar
  21. Urry, D.W. 1971. The gramicidin A transmembrane channel: A proposed πL,D-helix.Proc. Nat. Acad. Sci. USA 68:672Google Scholar
  22. 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 69:1610Google Scholar
  23. Veatch, W.R., Mathies, R., Eisenberg, M., Stryer, L., 1975. Simultaneous fluorescence and conductance studies of planar bilayer membranes containing a higly active and fluorescent analog of gramicidin A.J. Mol. Biol. 99:75Google Scholar
  24. Wünsch, E., Drees, F. 1966. Zur Synthese des Glucagons, X: Darstellung der Sequenz 22–29,Chem. Ber. 99:110Google Scholar
  25. Zingsheim, H.P., Neher, E. 1974. The equivalence of fluctuation analysis and chemical relaxation measurements: A kinetic study of pore formation in thin lipid membranes.Biophys. Chem. 2:197Google Scholar

Copyright information

© Springer-Verlag New York Inc 1979

Authors and Affiliations

  • H. -J. Apell
    • 1
  • E. Bamberg
    • 1
  • H. Alpes
    • 1
  1. 1.Fachbereich BiologieUniversität KonstanzKonstanzGermany

Personalised recommendations