Related Experiment Video
Updated: Jul 6, 2026
14:43
Combining Single-molecule Manipulation and Imaging for the Study of Protein-DNA Interactions
Published on: August 27, 2014
Local and translational dynamics in DNA-lipid assemblies monitored by solid-state and diffusion NMR
Cecília Leal1, Dick Sandström, Pernilla Nevsten
1Physical Chemistry I, Lund University, Sweden. cecilial@mrl.ucsb.edu
Biochimica Et Biophysica Acta
|March 6, 2008
Summary
DNA-lipid interactions, studied via NMR, reveal DNA is static but increases hydrocarbon chain disorder. Cationic lipid (DDA) diffusion slows, indicating segregation and altered dynamics within lipid membranes.
Area of Science:
- Biophysics
- Materials Science
- Biochemistry
Background:
- Understanding DNA-lipid interactions is crucial for gene delivery systems and membrane biophysics.
- Electrostatic interactions significantly influence the dynamic properties of complex lipid-DNA systems.
- Nuclear Magnetic Resonance (NMR) is a powerful tool for probing molecular dynamics in complex systems.
Purpose of the Study:
- To investigate the influence of electrostatic interactions on the dynamic properties of DNA-lipid complexes.
- To assess the local mobility and order of DNA and lipid components within lamellar membrane stacks.
- To elucidate the translational dynamics of lipids and water in DNA-lipid mixtures.
Main Methods:
- Solid-state NMR techniques, including WIdeline SEparation (WISE) and Separated Local Field (SLF) spectroscopy, were used to analyze molecular mobility and order.
- 31P-NMR confirmed the lamellar structure of the membrane stacks intercalated by DNA.
- Pulsed Field Gradient Stimulated Echo (PFG STE) NMR was employed to measure translational dynamics of lipids and water.
Main Results:
- DNA was found to be static, while inducing increased disorder in lipid hydrocarbon chains compared to lipid-only systems.
- Cationic lipid (DDA) chain order was more affected than zwitterionic lipid (DLPC) due to electrostatic attraction with DNA.
- Water diffusion coefficient was reduced, and lipid diffusion showed distinct fast (DLPC) and slow (DDA) components, indicating DNA-induced lipid segregation and altered dimensionality of diffusion.
Conclusions:
- DNA-lipid electrostatic interactions reduce long-range lipid mobility.
- These interactions locally enhance hydrocarbon chain dynamics by perturbing lipid packing.
- The study provides insights into the structural and dynamic consequences of DNA incorporation into lipid membranes.
More Related Videos
Related Concept Videos
01:19Protein Dynamics in Living Cells
Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET.
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
01:24Protein Diffusion in the Membrane
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...