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pH Fluctuations in Unilamellar Vesicles

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Part of the SpringerBriefs in Molecular Science book series (BRIEFSMOLECULAR)

Abstract

In this chapter pH fluctuations in small unilamellar vesicles (SUV) are theoretically estimated. We determine that these fluctuations are dependent on macroscopic variables as pH, pK a , buffer groups concentration and surface electrical potential. Basing on a previously reported definition of buffer electrical capacitance (Procopio & Fornés 1995) it is derived an equation which relates the pH fluctuation, the buffering power and the SUV size. From our results it is inferred that measurement of pH in small systems has to be performed near the pK of the buffer groups in order that the fluctuational errors be minimized. We show that pH fluctuations diminish with increasing the size of the SUV and the predicted pH fluctuations decrease as the surface potential becomes less negative as a consequence of decreasing density of charged groups in the inner vesicular surface. It is predicted that measurable effects will appear on the fluorescence detection due to protonic fluctuations close to the pH sensing region of the probes.

Keywords

pH fluctuations Buffer capacity Shift in the fluorescence spectrum 

References

  1. 1.
    Cevc, G., Marsh, D.: Phospholipid Bilayers. Wiley, New York (1987)Google Scholar
  2. 2.
    Fernández, M.S., Fromherz, P.: Lipoid pH-indicators as probes of electrical potential and polarity in micelles. J. Phys. Chem. 81, 1755 (1977)CrossRefGoogle Scholar
  3. 3.
    Fornés, J.A.: Fluctuation-dissipation theorem and the polarizability of rodlike polyelectrolytes: an electric circuit view. Phys. Rev. E 57, 2110 (1998)CrossRefGoogle Scholar
  4. 4.
    Grabowski, Z.R., Grabowska, A.: The Förster cycle reconsidered. Z. Phys. Chem. 101, 197 (1976)CrossRefGoogle Scholar
  5. 5.
    Gutknecht, J.: Proton conductance caused by long-chain fatty acids in phospholipid bilayer membranes. J. Membr. Biol. 106, 83 (1988)CrossRefGoogle Scholar
  6. 6.
    Gutman, M., Nachliel, E.: The dynamic aspects of proton transfer processes. Biochim. Biophys. Acta 1015, 391 (1990)CrossRefGoogle Scholar
  7. 7.
    Hamilton, J.A.: Fatty acid transport: difficult or easy? J. Lipid Res. 39, 467 (1998)Google Scholar
  8. 8.
    Hamilton, J.A., Cistola, D.P.: Transfer of oleic acid between albumin and phospholipid vesicles. Proc. Natl. Acad. Sci. 83, 82 (1986)CrossRefGoogle Scholar
  9. 9.
    Kamp, F., Hamilton, J.A.: pH gradients across phospholipid membranes caused by fast flip-flop of un-ionized fatty acids. Proc. Natl. Acad. Sci. 89, 11367 (1992)CrossRefGoogle Scholar
  10. 10.
    Kamp, F., Hamilton, J.A.: Movement of fatty acids, fatty acids analogues, and bile acids across phospholipid bilayers. Biochemistry 32, 11074 (1993)CrossRefGoogle Scholar
  11. 11.
    Kamp, F., Zakim, D., Zhang, F., Noy, N., Hamilton, J.A.: Fatty acid flip-flop in phospholipid bilayers is extremely fast. Biochemistry 34, 11928 (1995)CrossRefGoogle Scholar
  12. 12.
    Kraayenhof, R., Sterk, G.J., Sang, H.W.F.: Probing biomembrane interfacial... at varing distance from the membrane surface. Biochemistry 32, 10057 (1993)CrossRefGoogle Scholar
  13. 13.
    Kirkwood, J.G., Shumaker, J.B.: Forces between protein molecules in solution arising from fluctuations in proton charge and configuration. Proc. Natl. Acad. Sci. 38, 863 (1952)CrossRefGoogle Scholar
  14. 14.
    Mitchell, P., Moyle, J.: Estimation of membrane potential and pH difference across the cristae membrane of rat liver Biochem. J. 104, 588 (1967)Google Scholar
  15. 15.
    Miyazaki, J., Hideg, K., Marsh, D.: Interfacial ionization and partitioning of membrane-bound local anaesthetics. Biochim. Biophys. Acta 1103, 62 (1984)CrossRefGoogle Scholar
  16. 16.
    Procopio, J., Fornés, J.A.: Fluctuation-dissipation theorem imposes high-voltage fluctuations in biological ionic channels. Phys. Rev. E 51, 829 (1995)CrossRefGoogle Scholar
  17. 17.
    Procopio, J., Fornés, J.A.: Fluctuations of the proton- electromotive force across the inner mitochondrial membrane. Phys. Rev. E 55, 6285 (1997)CrossRefGoogle Scholar
  18. 18.
    Putnam, R.W.: In: Sperelakis, N. (ed.) Cell Physiology Source Book. Academic, New York (1998)Google Scholar
  19. 19.
    Rettig, W., Lapouyade, R.: Fluorescence probes based in TICT states. Chap. 5 In: Lakowicz, J.R. (ed.) Topics in Fluorescence Spectroscopy, vol. 4. Plenum Press, New York (1994)Google Scholar
  20. 20.
    Szmacinski, H., Lakowicz, J. R.: Lifetime-based sensing, Chap. 10 In: Lakowicz, J. R. (ed.) Topics in Fluorescence Spectroscopy, vol. 4. Plenum Press, New York (1994)Google Scholar
  21. 21.
    Tanford, C.: The interpretation of hydrogen ion titration curves of proteins. Adv. Protein Chem. 17, 69 (1962)CrossRefGoogle Scholar
  22. 22.
    Timasheff, S.N.: In: Biological Polyelectrolytes, vol. 3, Chap. 1 Marcel Dekker, New York (1970)Google Scholar
  23. 23.
    Thelen, M., Petrone, G., O’Shea, P.S., Azzi, A.: The use of fluoresce in dipalmitoylphosphatidylethanolamine for measuring pH-changes in the internal compartment of phospholipid vesicles. Biochim. Biochim. Biophys. Acta 766, 161 (1984)CrossRefGoogle Scholar
  24. 24.
    Van der Donckt, E.: Acid-base-properties of excited states. Prog. React. Kinet. 5, 273 (1970)Google Scholar

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© Springer International Publishing Switzerland 2017

Authors and Affiliations

  1. 1.Federal University of GoiásGoiâniaBrazil

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