Related Experiment Video
Updated: May 22, 2026

CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
The DNA-DNA spacing in gemini surfactants-DOPE-DNA complexes
Petra Pullmannová1, Sergio S Funari, Ferdinand Devínsky
1Department of Physical Chemistry of Drugs, Comenius University, Bratislava, Slovakia. pullmannova@fpharm.uniba.sk
Abstract:
Gemini surfactants from the homologous series of alkane-α,ω-diyl-bis(dodecyldimethylammonium bromide) (CnCS12, number of spacer carbons n=2-12) and dioleoylphosphatidylethanolamine (DOPE) were used for cationic liposome (CL) preparation. CLs condense highly polymerized DNA creating complexes. Small-angle X-ray diffraction identified them as condensed lamellar phase L(α)(C) in the studied range of molar ratios CnGS12/DOPE in the temperature range 20-60°C. The DNA-DNA distance (d(DNA)) is studied in dependence to CnGS12 spacer length and membrane surface charge density. The high membrane surface charge densities (CnGS12/DOPE=0.35 and 0.4mol/mol) lead to the linear dependence of d(DNA) vs. n correlating with the interfacial area of the CnGS12 molecule.
Related Concept Videos
Single-Strand DNA Binding Proteins
DNA Base Pairing
Maxam-Gilbert Sequencing
Challenges of the Maxam-Gilbert Method
The...
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...

