Effects of sodium chloride on membrane fusion and on the formation of aggregates of potassium channel KcsA in membrane

Mobeen Raja , Elisabeth Vales

In the current study, we found that NaCl induces fast vesicle fusion and aggregation of the bacterial potassium channel KcsA in () membranes. Conventional gel electrophoresis and tryptophan fluorescence experiments were performed to detect NaClinduced aggregation or supramolecular complexes. Interestingly, in planar lipid bilayer, increasing NaCl concentration dramatically increased the total internal current indicating enhanced vesicle fusion and transfer of high number of channels to the lipid bilayer. Such channels were appeared in clusters of variable size exhibiting higher conductivity, increased open probability and efficient blocking by K-channel blocker tetraethylammonium (TEA). Furthermore, NaCl-induced KcsA aggregation was found to be specific for membrane as compared to the artificial membrane system. Our preliminary data suggest the role of NaCl in formation of KcsA aggregates as well as in enhancement of membrane fusion capability in membranes.

Mots clés: Potassium channel KcsA; lipid; Sodium chloride; Aggregation; Phosphatidylethanolamine; Phosphatidylglycerol; Phosphatidylcholine; Vesicle fusion

Mobeen Raja, Elisabeth Vales. Effects of sodium chloride on membrane fusion and on the formation of aggregates of potassium channel KcsA in membrane. Biophysical Chemistry, 2009, 142 (1-3), pp.46. ⟨10.1016/j.bpc.2009.03.005⟩. ⟨hal-00528545⟩