Study on the Application of Electric Field to Giant Vesicles Comprised of 1,2-Dilauroyl-Sn-Glycero-3-Phosphatidylcholine Using Optical Fluorescence Microscopy

Abstract

The influence of alternating electric field (AC) in the structure and dynamics of giant unilamellar vesicles (GUVs) comprised of 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine (DLPC) is reported. The investigations were conducted by using optical fluorescence microscopy as the method of analysis. The lipid membrane of the DLPC GUVs at the fluid phase can be deformed and they migrate towards the electrodes under AC electric field. Nevertheless, membrane disruption or vesicle fusion was never noticed. The addition of concentrated glucose solution influences the osmotic pressure of the system leading to the formation of filaments at the outer region of the GUVs. These long flexible cylinders do not retract spontaneously. However, the application of AC electric field (20 V/mm, 20 Hz) enables the filaments to be retracted back to the GUVs membrane at a calculated speed of 0.18 µm.s -1

Jaburetox, a natural insecticide derived from Jack Bean Urease, activates voltage-gated sodium channels to modulate insect behavior

“…Later on we described that JBU and Jbtx form cation-selective ion channels in planar lipid bilayers with conductances in the range found for physiological potassium channels (Piovesan et al, 2014). Moreover, JBU and Jbtx are able to insert themselves into the lipid bilayers of multilamellar liposomes, thereby affecting physicochemical properties such as the number of lamellae and the membrane's fluidity (Micheletto et al, 2017). Our data showing the absence of a fast decrease in the resting membrane potential during the voltage clamp protocols suggest that, even if a pore forming activity could be involved in Jbtx's entomotoxicity, the main component to its neurotoxicity appears to involve alteration of the gating properties of sodium channels.…”