Potassium transport through lipid bilayer membranes facilitated by tentoxin dimers. A new mechanism of ion carrier transport?
The cyclic tetrapeptide tentoxin at concentrations greater than 5 X 10(-7) M selectively increases the ion conductivity for potassium of lipid bilayer membranes, while the naturally occurring derivative dihydrotentoxin has no influence on this property. Current-voltage curves, zero-current potential and charge-pulse measurements were used to characterize the action of tentoxin. The results suggest that a new mechanism of facilitated ion transport operates. The model of tentoxin dimerization and tentoxin-K+ association developed is in contradiction to the model of tentoxin pore formation described recently by Heitz et al. (Biophys. Chem. 23 (1986) 245).
Klotz
M G
MG
Department of Plant Biophysics, Friedrich Schiller University, Jena DDR, G.D.R.
Müller
E
E
Liebermann
B
B
D004553:Electric Conductivity; D007700:Kinetics; D008051:Lipid Bilayers; D008954:Models, Biological; D009183:Mycotoxins; D010456:Peptides, Cyclic; D011188:Potassium
D008051:Lipid Bilayers; D009183:Mycotoxins; D010456:Peptides, Cyclic; C003384:tentoxin; D011188:Potassium