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Interactions between DNA and nonionic ethylene oxide surfactants are predominantly repulsive
Alexandra H E Machado1, Dan Lundberg, António J Ribeiro
1Laboratory of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal. alexandra.machado@fkem1.lu.se
Langmuir : the ACS Journal of Surfaces and Colloids
|August 11, 2010
Summary
Interactions between DNA and nonionic ethylene oxide surfactants are weakly repulsive, primarily due to steric effects. Hydrophobic interactions play a minor attractive role, especially with single-stranded DNA.
Area of Science:
- Biophysical chemistry
- Polymer science
Background:
- Nonionic surfactants are widely used in biological applications.
- Understanding DNA-surfactant interactions is crucial for various biotechnological processes.
Purpose of the Study:
- To investigate the interactions between double-stranded (ds) and single-stranded (ss) DNA and nonionic ethylene oxide (EO) surfactants.
- To elucidate the contributions of hydrophobic and steric effects to these interactions.
Main Methods:
- Cloud point measurements of C(12)E(5) in the presence of DNA.
- DNA partitioning studies between surfactant-rich and surfactant-poor phases.
- Surface tensiometry to assess micellization.
- DNA melting experiments with C(12)E(8) to evaluate DNA stability.
Main Results:
- DNA presence slightly decreased the cloud point of C(12)E(5), with a more pronounced effect for dsDNA.
- DNA preferentially partitioned into the surfactant-poor phase.
- Neither DNA form induced surfactant micellization.
- C(12)E(8) did not alter the relative stabilities of ssDNA and dsDNA.
Conclusions:
- The net interaction between DNA and nonionic EO surfactants is weakly repulsive, mainly due to steric repulsion.
- A minor attractive component, likely hydrophobic, was observed, particularly for ssDNA.
- Results suggest minimal impact of these surfactants on DNA structural stability.
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