Abstract/Summary

Creating effective fungal membrane models for neutron and X-ray reflectometry experiments is a key step in the development of the new antifungal pharmaceuticals and agrochemicals to allow in vitro investigation of mode of interaction with target cells. The structure of the obtained models depends on the properties of the used lipids and the final composition of the leaflets, and can be subject to the spontaneous translocation of phospholipids across the bilayer. The effect of phospholipid acyl chain unsaturation and the presence of steroid in the membrane on the bilayer asymmetry were examined by means of neutron reflectometry (NR). The measurements showed that membrane stability was higher if a zwitterionic, saturated acyl chain phospholipid is present as the inner leaflet. Furthermore, membrane asymmetry was higher in case of the fully saturated lipid systems. As a result, membrane models consisting of fully saturated acyl chains within the inner leaflet are recommended as the starting point for subsequent studies of antifungal interactions due to the models’ simplicity and their relative stability, thus allowing better control over the exact lipid composition facing the tested antifungal.