Related Experiment Video
Updated: Jul 26, 2026
08:29
Generation of Cationic Nanoliposomes for the Efficient Delivery of In Vitro Transcribed Messenger RNA
Published on: February 1, 2019
Chiral DNA packaging in DNA-cationic liposome assemblies.
N J Zuidam1, Y Barenholz, A Minsky
1Department of Biochemistry, The Hebrew University, Hadassah Medical School, P.O. Box 12272, Jerusalem, Israel. nicolaas@cc.huji.il
FEBS Letters
|September 3, 1999
Summary
Cationic liposomes alter DNA structure, forming novel C-motif and cholesteric phases. These DNA-lipid assemblies are key for effective genetic material delivery into cells.
Area of Science:
- Biophysical Chemistry
- Molecular Biology
- Materials Science
Background:
- Lipid composition and charge ratio critically influence DNA-lipid assembly structure.
- Efficient cellular delivery of genetic material depends on these structural features.
Purpose of the Study:
- To investigate the structural transformations of DNA within cationic liposomes.
- To elucidate the relationship between DNA-lipid assembly structure and transfection efficiency.
Main Methods:
- Circular dichroism spectroscopy was employed to analyze DNA conformation.
- Structural modeling was used to propose DNA packaging mechanisms.
Main Results:
- Positively-charged liposomes induced a B-to-C conformational transition in DNA.
- Effective liposomes, containing helper lipids, caused DNA condensation into a left-handed cholesteric-like phase.
- A structural model revealed two coexisting DNA packaging modes.
Conclusions:
- DNA conformation and packaging are modulated by lipid composition and charge.
- Structural changes in DNA-lipid assemblies directly impact their function in genetic delivery.
- Subtle changes in supramolecular assembly components significantly alter structure-function relationships.
Related Concept Videos
00:58Genomic DNA in Eukaryotes
Eukaryotes have large genomes compared to prokaryotes. To fit their genomes into a cell, eukaryotic DNA is packaged extraordinarily tightly inside the nucleus. To achieve this, DNA is tightly wound around proteins called histones, which are packaged into nucleosomes that are joined by linker DNA and coil into chromatin fibers. Additional fibrous proteins further compact the chromatin, which is recognizable as chromosomes during certain phases of cell division.
00:58DNA Packaging
Overview
00:58DNA Packaging
Overview
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
01:32Chromatin Packaging
Each human somatic cell contains 6 billion base pairs of DNA. Each base pair is 0.34 nm long, meaning each diploid cell contains a staggering 2 meters of DNA. This long DNA strand is packed inside a nucleus measuring only 10-20 microns in diameter with the help of specialized DNA-binding proteins called histones. Together they form a compact DNA-protein complex called chromatin. The chromatin is further compacted into higher-order structures. The highest level of compaction is achieved during...