The Journal of Membrane Biology

, Volume 114, Issue 3, pp 195–203

Surface dielectric constant, surface hydrophobicity and membrane fusion

  • S. Ohki
  • K. Arnold

DOI: 10.1007/BF01869214

Cite this article as:
Ohki, S. & Arnold, K. J. Membrain Biol. (1990) 114: 195. doi:10.1007/BF01869214


Membrane fusion induced by ions and its associated membrane property, surface dielectric constant, were studied with the use of acidic and neutral phospholipid vesicles. The fusion of vesicles was monitored by utilizing two fluorescence fusion assays: fluorescence content mixing method and fluorescence labelled membrane component dilution method. For the surface dielectric constant measurements, a fluorescence method was used which detected the environmental effect on the membrane surface upon the addition of various fusogenic cations. Also, the effects of poly-(ethylene glycol) on both fusion and surface dielectric properties were examined. It was found that the extent of fusion correlated well with the degree of lowering in the dielectric constant of the surface membrane, which corresponds to the increase in hydrophobicity of the membrane surface. This agrees with the previously obtained experimental results that the increase in interfacial tension of the membrane, which also corresponds to the increase in surface hydrophobicity, correlates with the extent of membrane fusion.

Key Words

lipid vesicle fusionsurface dielectric constanthydrophobicitycationspoly-(ethylene glycol)

Copyright information

© Springer-Verlag New York Inc 1990

Authors and Affiliations

  • S. Ohki
    • 1
  • K. Arnold
    • 1
  1. 1.Department of Biophysical Sciences, School of MedicineState University of New York at BuffaloBuffalo
  2. 2.Institute of BiophysicsKarl-Marx UniversityLeipzigDDR