Structural thermodynamics of lamellar cationic lipid-DNA complex: DNA compressibility modulus
| Autor: | M. Hernández-Contreras, O. González-Amezcua |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Macromolecular Substances
Entropy Static Electricity Biophysics Molecular Conformation General Physics and Astronomy Thermodynamics Electrolyte chemistry.chemical_compound Static electricity Electrochemistry Lamellar structure Physics::Chemical Physics Physical and Theoretical Chemistry chemistry.chemical_classification Ions Quantitative Biology::Biomolecules Models Statistical Aqueous two-phase system Water DNA Quantitative Biology::Genomics Lipids Condensed Matter::Soft Condensed Matter chemistry Ionic strength Compressibility Physical chemistry Nucleic Acid Conformation Adsorption Counterion Isoelectric Focusing |
| Zdroj: | The Journal of chemical physics. 123(22) |
| ISSN: | 0021-9606 |
| Popis: | We have studied theoretically the compressibility modulus B of DNA and complexation adsorption isotherms of DNA and lipids, as a function of DNA spacing d(DNA) and NaCl electrolyte concentration, respectively, in isoelectric states of lamellar DNA/cationic lipid (CL) self-assemblies. The electrostatic free energy derived from the Poisson-Boltzmann theory predicts partial agreement with measured B values for interhelical separations d(DNA)>33 A when use is made of a fit of hydration repulsion from bulk DNA hexagonal phases in solution. For lower interchain separations the prediction worsens due to the hydration interaction that overcomes the electrostatic contribution. An exact match of the system's counterion electrochemical potentials and the coions of salt in aqueous phase leads to the electrostatic part of the free energy that renders isotherms of d(DNA) versus ionic strength in qualitative consistency with general trends of available experimental data of CL-DNA complexes. |
| Databáze: | OpenAIRE |
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