Advertisement

Journal of Biosciences

, Volume 8, Issue 1–2, pp 315–327 | Cite as

Studies involving the electrostatic potential of valinomycin

  • N. Sreerama
  • S. Vishveshwara
Article

Abstract

The electrostatic potential of valinomycin in various conformations as obtained by the crystal structures (uncomplexed, complexed) and theoretical considerations have been evaluated and compared. The potential energy profiles along the æ axis of the bracelet-like structures show a systematic variation from the uncomplexed to the complexed structure. This type of conformational change and the potential variation are probably associated with different states of ion transport, like the capture and release of ions by the ionophore. Also, the asymmetry of the molecule due to D-HyIV on one side and L-Lac on the other side is reflected in the potential values along the Z-axis, the magnitude of which, is considerable in the uncomplexed structure. The evaluation of the potential at the ab-initio level on smaller fragments indicate that the order of liganding capacity of oxygen is amide > ether > ester. Also, the inductive effects due to alkyl substitution is negligible as evidenced by the potential studies on the substituted amides and esters.

Keywords

Valinomycin electrostatic potential liganding capacity 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Blow, D. M. (1960)Acta. Crystalogr.,13, 168.CrossRefGoogle Scholar
  2. Catalan, J. and Yanez, M. (1980)Tetrahedron,36, 665.CrossRefGoogle Scholar
  3. Devarajan, S., Nair, C. M. K., Easwaran, K. R. K. and Vijayan, M. (1980)Nature (London),286, 640.CrossRefGoogle Scholar
  4. Devarajan, S. and Easwaran, K. R. K. and Vijayan, M. (1984)Int. J. Peptide Protein Res.,23, 324.CrossRefGoogle Scholar
  5. Etchebest, C., Lavery, R. and Pullman, A. (1982)Stud. Biophys.,90, 7.Google Scholar
  6. Hamilton, J. A., Sabesan, M. N. and Steinrauf, L. K. (1981)J. Am. Chem. Soc.,103, 5880.CrossRefGoogle Scholar
  7. Hayes, D. M. and Kollman, P. A. (1976)J. Am. Chem. Soc.,98, 3335.CrossRefGoogle Scholar
  8. Hehre, W. J., Stewart, R. F. and Pople, J. A. (1969)J. Chem. Phys.,51, 2657.CrossRefGoogle Scholar
  9. Karle, I. L. (1975)J. Am. Chem. Soc.,97, 4379.CrossRefGoogle Scholar
  10. Mayers, D. F. and Urry, D. W. (1972)J. Am. Chem. Soc.,94, 77.CrossRefGoogle Scholar
  11. Neupert-Laves, K. and Dobbler, M. (1975)Helv. Chim. Acta.,58, 432.CrossRefGoogle Scholar
  12. Ovchinnikov, Yu. A. and Ivanov, V. T. (1975)Tetrahedron,31, 2177.CrossRefGoogle Scholar
  13. Ovichinnikov, Yu. A., Ivanov, V. T., and Shkrob, A. M. (1974)Membrane active complexones, (Amsterdam: Elsevier).Google Scholar
  14. Perricaudet, M. and Pullman, A. (1973)FEBS Lett.,34, 222.CrossRefGoogle Scholar
  15. Scrocco, E. and Tomasi, J. (1973)Top. Curr. Chem.,42, 95.Google Scholar
  16. Smith, G. D., Dnax, W. L., Langs, D. A., De Titta, G. T., Edmonds, J. W., Rohrer, D. C. and Weeks, C. M. (1975)J. Am. Chem. Soc.,97, 7242.CrossRefGoogle Scholar
  17. Srebrenik, S., Weinstein, H. and Pauncz, (1973)Chem. Phys. Lett.,20, 419.CrossRefGoogle Scholar
  18. Steinrauf, L. K., Hamilton, J. A. and Sabesan, M. N. (1982)J. Am. Chem. Soc.,104, 4085.CrossRefGoogle Scholar
  19. Sundaram, K. and Tyagi, K. S. (1978)Int. J. Quantum Chem.,13, 17.CrossRefGoogle Scholar
  20. Szabo, G., Eisenman, G., Laprade, R., Ciani, S. M. and Krasne, S. (1973) inMembranes (ed. George Eisenman) (New York: Marcel Dekker Inc) p. 291.Google Scholar

Copyright information

© Indian Academy of Sciences 1985

Authors and Affiliations

  • N. Sreerama
    • 1
  • S. Vishveshwara
    • 1
  1. 1.Molecular Biophysics UnitIndian Institute of ScienceBangaloreIndia

Personalised recommendations