Abstract Title

Lipid Composition Modulates the Functionality of Lysenin Channels

Disciplines

Biophysics | Molecular Biology

Abstract

This research work was undertaken to demonstrate that the composition of the lipid environment, modulates the response of voltage-gated channels to external stimuli. In our electrophysiology experiments, we employed planar bilayer lipid membranes for which we changed the lipid composition by adding neutral lipids, charged lipids, and small organic molecules. After self-insertion of lysenin channels into the bilayers, we assessed their response to external voltage stimuli ranging from -60 to +60 mV. Our experiments indicated that neutral lipids favor a significant shift of the voltage required to induce channel gating. In contrast addition of anionic lipids shift the voltage induced gating towards lower values. A similar effect has been observed upon addition of menthol in the support membrane. The theoretical fit of the experimental data with a Boltzmann distribution of the open probability suggests significant changes of the free energy in different lipid environments. In conclusion the functionality of the voltage-gated channels may be adjusted not only by altering their primary structure, but also by changing the composition of the lipid microenvironment in which they function.

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Lipid Composition Modulates the Functionality of Lysenin Channels

This research work was undertaken to demonstrate that the composition of the lipid environment, modulates the response of voltage-gated channels to external stimuli. In our electrophysiology experiments, we employed planar bilayer lipid membranes for which we changed the lipid composition by adding neutral lipids, charged lipids, and small organic molecules. After self-insertion of lysenin channels into the bilayers, we assessed their response to external voltage stimuli ranging from -60 to +60 mV. Our experiments indicated that neutral lipids favor a significant shift of the voltage required to induce channel gating. In contrast addition of anionic lipids shift the voltage induced gating towards lower values. A similar effect has been observed upon addition of menthol in the support membrane. The theoretical fit of the experimental data with a Boltzmann distribution of the open probability suggests significant changes of the free energy in different lipid environments. In conclusion the functionality of the voltage-gated channels may be adjusted not only by altering their primary structure, but also by changing the composition of the lipid microenvironment in which they function.