Biophysical Journal 54: 25-33 (1988)
© 1988 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Benz, R Search for Related Content PubMed PubMed Citation Articles by Benz, R

Structural requirement for the rapid movement of charged molecules across membranes. Experiments with tetraphenylborate analogues.

Lehrstuhl für Biotechnologie, Universität Würzburg, Federal Republic of Germany.

ABSTRACT

Charge-pulse experiments were performed in the presence of structural analogues of tetraphenylborate (TPB) on membranes made of dioleoyl phosphatidylethanolamine and dioleoyl phosphatidylcholine. The analysis of the experimental results using a previously proposed model allowed the calculation of the partition coefficient, beta, and of the translocation rate constant, kappa i. The temperature dependence of the partition coefficients was used to calculate the thermodynamics of the adsorption of the lipophilic ions to the membranes. The analysis of the translocation rate constants obtained at different temperatures yielded detailed information on the free energy of the TPB-analogues within artificial lipid bilayer membranes, and on the activation energy of the translocation rate constants. The adsorption of the different TPB-analogues to the membranes was only slightly affected by their structure, whereas a dramatic influence of the structure on the free energy of the lipophilic ions within the membranes was observed. The free energy of the ions in the membranes decreased from triphenylcyanoborate (TPCB) to tetrakis(3-trifluoromethylphenyl)borate (TTFPB) by more than 31 kJ/mol (7.4 kcal/mol). This could be concluded from the observed increase in the translocation rate constant by almost six orders of magnitude. The change of the free energy in the membrane was used for the estimation of an effective radius of the TPB-analogues with respect to TPB.

This article has been cited by other articles:

				S. Mennerick, M. Lamberta, H.-J. Shu, J. Hogins, C. Wang, D. F. Covey, L. N. Eisenman, and C. F. Zorumski Effects on Membrane Capacitance of Steroids with Antagonist Properties at GABAA Receptors Biophys. J., July 1, 2008; 95(1): 176 - 185. [Abstract] [Full Text] [PDF]

				J. Schamberger and R. J. Clarke Hydrophobic Ion Hydration and the Magnitude of the Dipole Potential Biophys. J., June 1, 2002; 82(6): 3081 - 3088. [Abstract] [Full Text] [PDF]