Skip to main content
Download PDF
  • Short communication
  • Published:

Kinetic models for stochastically modified ionic channels

Cellular & Molecular Biology Letters volume 13, pages 421–429 (2008)Cite this article

Abstract

Ionic channels form pores in biomembranes. These pores are large macromolecular structures. Due to thermal fluctuations of countless degrees-of-freedom of the biomembrane material, the actual form of the pores is permanently subject to modification. Furthermore, the arrival of an ion at the binding site can change this form by repolarizing the surrounding aminoacids. In any case the variations of the pore structure are stochastic. In this paper, we discuss the effect of such modifications on the channel conductivity. Applying a simple kinetic description, we show that stochastic variations in channel properties can significantly alter the ionic current, even leading to its substantial increase or decrease for the specific matching of some time-scales of the system.

References

  1. Cooper, A. Thermodynamic fluctuations in protein molecules. Proc. Natl. Acad. Sci. 73 (1976) 2740–2741.

    Article  PubMed  CAS  Google Scholar 

  2. Zheng, J. Patch Fluorometry: shedding new light on ion channels. Physiology 21 (2006) 6–12.

    Article  PubMed  CAS  Google Scholar 

  3. Levitt, D.G. Modeling of ion channels. J. Gen. Physiol. 113 (1999) 789–794.

    Article  PubMed  CAS  Google Scholar 

  4. Hille, B. Ionic channels of excitable membranes, 2nd edition, Sinauer Associates, 1992.

  5. Doering, C.R. and Gadoua, J.C. Resonant activation over a fluctuating barrier. Phys. Rev. Lett. 69 (1992) 2318–2321.

    Article  PubMed  Google Scholar 

  6. Astumian, R.D. and Bier, M. Matching a diffusive and a kinetic approach for escape over a fluctuating barrier. Phys. Rev. Lett. 71 (1993) 1649–1652.

    Article  PubMed  Google Scholar 

  7. Iwaniszewski, J. Escape over fluctuating barrier: limits of small and large correlation time. Phys. Rev. E. 54 (1996) 3173–3184.

    Article  CAS  Google Scholar 

  8. Iwaniszewski, J., Kaufman, I.K., McClintock, P.V.E. and McKane, A.J. Resonances while surmounting a fluctuating barrier. Phys. Rev. E. 61 (2000) 1170–1175.

    Article  CAS  Google Scholar 

  9. Kramers, H.A. Brownian motion in the field of force and the diffusion model of chemical reactions. Physica 7 (1940) 284.

    Article  CAS  Google Scholar 

  10. Brey, J.J. and Casado-Pascual, J. Resonant activation in a simple kinetic model. Phys. Rev. E 50 (1994) 116–120.

    Article  Google Scholar 

  11. Läuger, P., Stephan, W. and Frehland, E. Fluctuations of barrier structure in ionic channels. Biochim. Biophys. Acta 602 (1980) 167–180.

    Article  PubMed  Google Scholar 

  12. Iwaniszewski, J. Mean escape time over a fluctuating barrier. Phys. Rev. E. 68 (2003) 027105.

    Article  CAS  Google Scholar 

  13. French, R.J., Worley J.F.III, Wonderlin, W.F., Kularatna, A.S., Krueger, B.K. Ion permeation, divalent ion block, and chemical modification of single sodium channels. Description by single-and double-occupancy rate theory models. J. Gen. Physiol. 103 (1994) 447–470.

    Article  PubMed  CAS  Google Scholar 

  14. Kurata, Y., Sato, R., Hisatome, I. and Imanishi, S. Mechanisms of cation permeation in cardiac sodium channel: Description by dynamic pore model. Biophys. J. 77 (1999) 1885–1904.

    PubMed  CAS  Google Scholar 

  15. Mironov, S.L. Conformational model for ion permeation in membrane channels: A comparison with multi-ion models and applications to calcium channel permeability. Biophys. J. 63 (1992) 485–496.

    Article  PubMed  CAS  Google Scholar 

  16. Lee, K. and Sung, W. Effects of nonequilibrium fluctuations on ionic transport through biomembranes. Phys. Rev. E 60 (1999) 4681–4686.

    Article  CAS  Google Scholar 

  17. Moss, G.W.J. and Moczydlowski, E. Rectifying conductance substates in large conductance Ca2+-activated K+ channel: Evidence for a fluctuating barrier mechanism. J. Gen. Physiol. 107 (1996) 47–68.

    Article  PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Institute of Physics, Nicolaus Copernicus University, Grudziądzka 5, 87-100, Toruń, Poland

    Aleksander Wozinski & Jan Iwaniszewski

Authors
  1. Aleksander Wozinski
    View author publications

    You can also search for this author inPubMed Google Scholar

  2. Jan Iwaniszewski
    View author publications

    You can also search for this author inPubMed Google Scholar

Corresponding author

Correspondence to Aleksander Wozinski.

Additional information

Paper authored by participants of the international conference: International Workshop on Ionic Channels, Szczyrk, Poland, May 27–June 01, 2007. Publication cost was covered by the organisers of this meeting.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Wozinski, A., Iwaniszewski, J. Kinetic models for stochastically modified ionic channels. Cell Mol Biol Lett 13, 421–429 (2008). https://doiorg.publicaciones.saludcastillayleon.es/10.2478/s11658-008-0010-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doiorg.publicaciones.saludcastillayleon.es/10.2478/s11658-008-0010-0

Key words

Cellular & Molecular Biology Letters

ISSN: 1689-1392

Contact us