Related Experiment Video
Updated: Jul 3, 2026
12:43
Genetic and Biochemical Approaches for In Vivo and In Vitro Assessment of Protein Oligomerization: The Ryanodine Receptor Case Study
Published on: July 27, 2016
A method to evaluate a propidium iodide association with oligonucleotides and oligonucleotide-cationic lipid
Magda Przybylo1, Tomasz Borowik, Andrzej Okruszek
1Institute of Biomedical Engineering & Measurements, Wroclaw University of Technology, Wyb., Wyspianskiego 27, Wroclaw, Poland. magdalena.przybylo@pwr.wroc.pl
Current Drug Discovery Technologies
|August 5, 2008
Summary
Researchers developed a new method to measure how small molecules bind to nucleic acids, crucial for genetic therapies. This technique accurately quantifies molecular interactions in pharmacological formulations.
Area of Science:
- Pharmacology
- Biochemistry
- Molecular Biology
Background:
- Complex molecular ensembles are key in novel pharmacological formulations, particularly for genetic therapies.
- Effective drug delivery requires precise association between nucleic acids and formulation components for desired structure and properties.
- Assessing supramolecular aggregate formation necessitates robust quality control methodologies.
Purpose of the Study:
- To propose and validate a novel procedure for quantifying the association between small molecules and nucleic acids.
- To exemplify this method using propidium iodide and oligonucleotides.
- To evaluate oligonucleotide association with lipid aggregates.
Main Methods:
- Utilized fluorescence resonance energy transfer (FRET) between a fluorescein-labeled oligonucleotide (donor) and propidium iodide (acceptor).
- Employed acceptor-donor titration methodology to determine the propidium iodide binding constant.
- Applied the developed FRET-based method to assess oligonucleotide association with lipid aggregates, including quenching experiments.
Main Results:
- The calculated binding constants for propidium iodide and oligonucleotides were consistent with previously published values.
- Two distinct oligonucleotide populations were identified in all studied lipid samples.
- Oligonucleotide association with liposomes increased with cationic lipid content, plateauing above 20 mol%.
Conclusions:
- The developed FRET-based method accurately measures small molecule-nucleic acid binding constants.
- Lipid aggregate composition significantly influences oligonucleotide association and orientation.
- Surface charge density dictates the orientation of oligonucleotides within lipid bilayers.
