Physical Chemistry Properties of Liponucleosides Incorporated in Cell Membrane Models at the Air-Water Interface

Liponucleosides can help the anchoring of nucleic acid nitrogen bases into cell membranes for tailored nanobiotechnological applications. For that, specific knowledge on the biophysical details at the membrane surface is essential. Here, we employed lipid Langmuir monolayers as cell membrane models to investigate the insertion of five lipidated nucleosides, which varied in the type of the covalenty attached lipid group, the nucleobase, and the number of hydrophobic moieties attached. All five lipidated nucleosides were surface-active, forming stable monolayers, also being able to incorporate into dipalmitoylphosphatidylcholine (DPPC) monolayers. Four of them induced expansion in the surface pressure isotherm and caused the decrease in the surface compression modulus of DPPC. In contrast, one nucleoside with three alkyl chain modifications formed condensed monolayers and induced monolayer condensation and also an increase in the compression modulus for the lipid monolayer. These facts therefore reflected the importance of the ability of the nucleoside molecules to be accommodated in packed arrangements at the air-water interface. These results enable the possibility of tuning nucleic acid pairing by changing structural characteristics of the liponucleosides.