Folding of long DNA chains in the presence of distearyldimethylammonium bromide and unfolding induced by neutral liposomes

Melnikov, Sergey M.; Sergeyev, Vladimir G.; Mel'nikova, Yulia S; Yoshikawa, Kunio

doi:10.1039/a603753d

Cited by 43 publications

(33 citation statements)

References 32 publications

(8 reference statements)

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“…For instance, it was shown that the addition of an aqueous bu¡er solution [9], simple monovalent salts [24], synthetic polyacid [9] and neutral liposomes [25] induces the unfolding globule-coil transition in single linear DNA molecules. It was also presumed that the addition of anionic surfactant to the DNA-cationic surfactant globules will lead to DNA unfolding due to the formation of complexes between oppositely charged surfactants.…”

Section: Resultsmentioning

confidence: 99%

DNA conformational dynamics in the presence of catanionic mixtures

Melnikov¹,

Dias

Mel’nikova³

et al. 1999

FEBS Letters

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DNA conformational behavior in the presence of nonstoichiometric mixtures of two oppositely charged surfactants, cetyltrimethylammonium bromide and sodium octyl sulfate, was directly visualized in an aqueous solution with the use of a fluorescence microscopy technique. It was found that in the presence of cationic-rich catanionic mixtures, DNA molecules exhibit a conformational transition from elongated coil to compact globule states. Moreover, if the catanionic mixtures form positively charged vesicles, DNA is adsorbed onto the surface of the vesicles in a collapsed globular form. When anionic-rich catanionic mixtures are present in the solution, no change in the DNA conformational behavior was detected. Cryogenic transmission electron microscopy, as well as measurements of translational diffusion coefficients of individual DNA chains, supported our optical microscopy observations. z 1999 Federation of European Biochemical Societies.

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Section: Resultsmentioning

confidence: 99%

DNA conformational dynamics in the presence of catanionic mixtures

Melnikov¹,

Dias

Mel’nikova³

et al. 1999

FEBS Letters

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“…The final concentrations (DNA 0.25 μM in terms of nucleotide units; DAPI 0.25 μM) were kept constant throughout the fluorescence microscopy experiments. This concentration of DNA corresponds to half the concentration that has been used in some of the previous studies [11,13,16,17,[22][23][24][25], which makes the visualization of individual DNA molecules easier via fluorescence microscopy in our recent equipment. We note that the number of chains simultaneously visible with such equipment largely exceeds those observed with older setups.…”

Section: Sample Preparationmentioning

confidence: 99%

“…Chemical agents cause compaction by modifying electrostatic interactions between DNA segments, by modifying DNA-solvent interactions, by excluding volume to the worm-like coil (and/or counterions), by causing localized bending or distorsion of the helical structure, or by some combination of these effects. Compaction of DNA chains is induced in vitro by the addition of agents such as polyamines [8], multivalent metal cations [9], hydrophilic polymers [10], cationic polymers [11,12], catanionic liposomes [13], and cationic [14] and nonionic surfac-* Corresponding author. tants [15].…”

Section: Introductionmentioning

confidence: 99%

Cationic agents for DNA compaction

Gawęda

Morán

Pais

et al. 2008

Journal of Colloid and Interface Science

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Fluorescence microscopy was used to investigate the conformational changes of individual T4 DNA molecules induced by different compacting agents, namely the cationic surfactants, cetyltrimethylammonium bromide (CTAB) and chloride (CTAC), iron(III), lysozyme, and protamine sulfate. A protocol for establishing size estimates is suggested to obtain reproducible results. Observations show that in the presence of lysozyme and protamine sulfate, DNA molecules exhibit a conformational change from an elongated coil structure to compact globules, usually interpreted as a first-order transition. The maximum degree of compaction that is attained when iron(III) or CTAB (CTAC) are used as compacting agents is considerably smaller, and intermediate structures (less elongated coils) are visible even for high concentrations of these agents. Dynamic light scattering experiments were carried out, for some of the systems, to assess the reliability of size estimates from fluorescence microscopy.

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“…The general aspects of DNA compaction by cationic surfactants have been monitored by Yoshikawa s group (6,15,16,(30)(31)(32) and others and by our group recently (11,33). Some illustrative fluorescence micrographs are presented in Figure 6.…”

Section: Dna Is Compacted By Cationic Surfactantsmentioning

confidence: 99%

“…Observations for other polyion systems imply that the surfactant aggregates are more or less evenly distributed over different polymer molecules. However, for DNA the observations seem to imply a different behavior, i.e., a very uneven distribution of surfactant between different DNA molecules (15)(16)(17). In turn, such a double cooperativity implies that surfactant binding to a DNA molecule facilitates further binding.…”

Section: Dna Displays a Strong Associative Behavior With Cationic Surmentioning

confidence: 99%

DNA-lipid systems: A physical chemistry study

Dias

Antunes

Miguel

et al. 2002

Braz J Med Biol Res

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It is well known that the interaction of polyelectrolytes with oppositely charged surfactants leads to an associative phase separation; however, the phase behavior of DNA and oppositely charged surfactants is more strongly associative than observed in other systems. A precipitate is formed with very low amounts of surfactant and DNA. DNA compaction is a general phenomenon in the presence of multivalent ions and positively charged surfaces; because of the high charge density there are strong attractive ion correlation effects. Techniques like phase diagram determinations, fluorescence microscopy, and ellipsometry were used to study these systems. The interaction between DNA and catanionic mixtures (i.e., mixtures of cationic and anionic surfactants) was also investigated. We observed that DNA compacts and adsorbs onto the surface of positively charged vesicles, and that the addition of an anionic surfactant can release DNA back into solution from a compact globular complex between DNA and the cationic surfactant. Finally, DNA interactions with polycations, chitosans with different chain lengths, were studied by fluorescence microscopy, in vivo transfection assays and cryogenic transmission electron microscopy. The general conclusion is that a chitosan effective in promoting compaction is also efficient in transfection.

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Folding of long DNA chains in the presence of distearyldimethylammonium bromide and unfolding induced by neutral liposomes

Cited by 43 publications

References 32 publications

DNA conformational dynamics in the presence of catanionic mixtures

DNA conformational dynamics in the presence of catanionic mixtures

Cationic agents for DNA compaction

DNA-lipid systems: A physical chemistry study

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