Phase behavior of selected artificial lipids

The flexibility of biomembranes is based on the physical-chemical properties of their main components - glycerophospholipids. The structure of these modular amphiphilic molecules can be modified through organic synthesis making it possible to study specific physical-chemical effects in detail. In particular, the roles of the hydrophobic tails of the phospholipids and their hydrophobic/hydrophilic interfacial backbone on the phase behaviour are highlighted. The spatial orientation of the glycerol backbone changes from sn-1,2 to sn-1,3 phospholipids leading to an increase of the in-plane area of the molecule. The larger distance between the hydrophobic tails can lead to membrane leaflet interdigitation. The introduction of methyl side groups in the hydrophobic tails increases the fluidity of the bilayer. Depending on the position of the methyl branches partial interdigitation is observed. In the case of bolaamphiphiles, methyl side groups have a similar effect on the fluidity, but interdigitation cannot occur.