Lipid-Modified Peptide Nucleic Acids: Synthesis and Application to Programmable Liposome Fusion

Methods Mol Biol. 2020:2105:75-96. doi: 10.1007/978-1-0716-0243-0_5.

Abstract

Peptide nucleic acids (PNAs) can be modified with aliphatic lipid chains and designed to be water soluble and able to spontaneously insert into phospholipid bilayers. Liposomes with 1.5% negatively charged POPG can be driven to fuse and mix their inner content volumes via functionalization with such lipidated peptide nucleic acids (LiPNAs). During fusion, only low amounts of leakage occur (<5%). We describe here the synthesis and purification of such LiPNAs using an automated peptide synthesizer and the preparation of LiPNA functionalized liposomes. Further, we describe the measurement of LiPNA-induced fusion using a fluorescence-based assay for the content mixing between a liposome population with an encapsulated self-quenching fluorescent dye (SRB) and a buffer-filled liposome population.

Keywords: Content mixing assays; Lipid bilayer fusion; Lipidated PNA; Liposomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemistry Techniques, Synthetic*
  • Chromatography, High Pressure Liquid
  • Lipids / chemistry*
  • Liposomes / chemistry
  • Membrane Fusion
  • Oxidative Coupling
  • Peptide Nucleic Acids / chemical synthesis*
  • Peptide Nucleic Acids / chemistry
  • Peptide Nucleic Acids / isolation & purification

Substances

  • Lipids
  • Liposomes
  • Peptide Nucleic Acids