TY - JOUR A1 - Zakrevskyy, Yuriy A1 - Kopyshev, Alexey A1 - Lomadze, Nino A1 - Morozova, Elena A1 - Lysyakova, Liudmila A1 - Kasyanenko, Nina A1 - Santer, Svetlana T1 - DNA compaction by azobenzene-containing surfactant JF - Physical review : E, Statistical, nonlinear and soft matter physics N2 - We report on the interaction of cationic azobenzene-containing surfactant with DNA investigated by absorption and fluorescence spectroscopy, dynamic light scattering, and atomic force microscopy. The properties of the surfactant can be controlled with light by reversible switching of the azobenzene unit, incorporated into the surfactant tail, between a hydrophobic trans (visible irradiation) and a hydrophilic cis (UV irradiation) configuration. The influence of the trans-cis isomerization of the azobenzene on the compaction process of DNA molecules and the role of both isomers in the formation and colloidal stability of DNA-surfactant complexes is discussed. It is shown that the trans isomer plays a major role in the DNA compaction process. The influence of the cis isomer on the DNA coil configuration is rather small. The construction of a phase diagram of the DNA concentration versus surfactant/DNA charge ratio allows distancing between three major phases: colloidally stable and unstable compacted globules, and extended coil conformation. There is a critical concentration of DNA above which the compacted globules can be hindered from aggregation and precipitation by adding an appropriate amount of the surfactant in the trans configuration. This is because of the compensation of hydrophobicity of the globules with an increasing amount of the surfactant. Below the critical DNA concentration, the compacted globules are colloidally stable and can be reversibly transferred with light to an extended coil state. Y1 - 2011 U6 - https://doi.org/10.1103/PhysRevE.84.021909 SN - 1539-3755 VL - 84 IS - 2 PB - American Physical Society CY - College Park ER - TY - GEN A1 - Kasyanenko, Nina A1 - Unksov, Ivan A1 - Bakulev, Vladimir A1 - Santer, Svetlana T1 - DNA interaction with head-to-tail associates of cationic surfactants prevents formation of compact particles T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Cationic azobenzene-containing surfactants are capable of condensing DNA in solution with formation of nanosized particles that can be employed in gene delivery. The ratio of surfactant/DNA concentration and solution ionic strength determines the result of DNA-surfactant interaction: Complexes with a micelle-like surfactant associates on DNA, which induces DNA shrinkage, DNA precipitation or DNA condensation with the emergence of nanosized particles. UV and fluorescence spectroscopy, low gradient viscometry and flow birefringence methods were employed to investigate DNA-surfactant and surfactant-surfactant interaction at different NaCl concentrations, [NaCl]. It was observed that [NaCl] (or the Debye screening radius) determines the surfactant-surfactant interaction in solutions without DNA. Monomers, micelles and non-micellar associates of azobenzene-containing surfactants with head-to-tail orientation of molecules were distinguished due to the features of their absorption spectra. The novel data enabled us to conclude that exactly the type of associates (together with the concentration of components) determines the result of DNA-surfactant interaction. Predomination of head-to-tail associates at 0.01 M < [NaCl] < 0.5 M induces DNA aggregation and in some cases DNA precipitation. High NaCl concentration (higher than 0.8 M) prevents electrostatic attraction of surfactants to DNA phosphates for complex formation. DAPI dye luminescence in solutions with DNA-surfactant complexes shows that surfactant tails overlap the DNA minor groove. The addition of di- and trivalent metal ions before and after the surfactant binding to DNA indicate that the bound surfactant molecules are located on DNA in islets T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 940 KW - azobenzene trimethylammonium bromide KW - head-to-tail surfactant associates KW - DNA KW - ionic strength KW - multivalent ions Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459806 SN - 1866-8372 IS - 940 ER - TY - JOUR A1 - Kasyanenko, Nina A1 - Unksov, Ivan A1 - Bakulev, Vladimir A1 - Santer, Svetlana T1 - DNA interaction with head-to-tail associates of cationic surfactants prevents formation of compact particles JF - Molecules N2 - Cationic azobenzene-containing surfactants are capable of condensing DNA in solution with formation of nanosized particles that can be employed in gene delivery. The ratio of surfactant/DNA concentration and solution ionic strength determines the result of DNA-surfactant interaction: Complexes with a micelle-like surfactant associates on DNA, which induces DNA shrinkage, DNA precipitation or DNA condensation with the emergence of nanosized particles. UV and fluorescence spectroscopy, low gradient viscometry and flow birefringence methods were employed to investigate DNA-surfactant and surfactant-surfactant interaction at different NaCl concentrations, [NaCl]. It was observed that [NaCl] (or the Debye screening radius) determines the surfactant-surfactant interaction in solutions without DNA. Monomers, micelles and non-micellar associates of azobenzene-containing surfactants with head-to-tail orientation of molecules were distinguished due to the features of their absorption spectra. The novel data enabled us to conclude that exactly the type of associates (together with the concentration of components) determines the result of DNA-surfactant interaction. Predomination of head-to-tail associates at 0.01 M < [NaCl] < 0.5 M induces DNA aggregation and in some cases DNA precipitation. High NaCl concentration (higher than 0.8 M) prevents electrostatic attraction of surfactants to DNA phosphates for complex formation. DAPI dye luminescence in solutions with DNA-surfactant complexes shows that surfactant tails overlap the DNA minor groove. The addition of di- and trivalent metal ions before and after the surfactant binding to DNA indicate that the bound surfactant molecules are located on DNA in islets. KW - azobenzene trimethylammonium bromide KW - head-to-tail surfactant associates KW - DNA KW - ionic strength KW - multivalent ions Y1 - 2018 U6 - https://doi.org/10.3390/molecules23071576 SN - 1420-3049 VL - 23 IS - 7 PB - MDPI CY - Basel ER - TY - JOUR A1 - Kasyanenko, Nina A1 - Lysyakova, Liudmila A1 - Ramazanov, Ruslan A1 - Nesterenko, Alexey A1 - Yaroshevich, Igor A1 - Titov, Evgenii A1 - Alexeev, G. A1 - Lezov, Andrey A1 - Unksov, I. T1 - Conformational and Phase Transitions in DNA-Photosensitive Surfactant Solutions: Experiment and Modeling JF - Biopolymers N2 - DNA binding to trans- and cis-isomers of azobenzene containing cationic surfactant in 5 mM NaCl solution was investigated by the methods of dynamic light scattering (DLS), low-gradient viscometry (LGV), atomic force microscopy (AFM), circular dichroism (CD), gel electrophoresis (GE), flow birefringence (FB), UV-Vis spectrophotometry. Light-responsive conformational transitions of DNA in complex with photosensitive surfactant, changes in DNA optical anisotropy and persistent length, phase transition of DNA into nanoparticles induced by high surfactant concentration, as well as transformation of surfactant conformation under its binding to macromolecule were studied. Computer simulations of micelles formation for cis- and trans-isomers of azobenzene containing surfactant, as well as DNA-surfactant interaction, were carried out. Phase diagram for DNA-surfactant solutions was designed. The possibility to reverse the DNA packaging induced by surfactant binding with the dilution and light irradiation was shown. (c) 2014 Wiley Periodicals, Inc. Biopolymers 103: 109-122, 2015. KW - DNA-surfactant complexes KW - light-induced DNA de-compaction KW - phase diagram KW - DNA volume and persistent length Y1 - 2015 U6 - https://doi.org/10.1002/bip.22575 SN - 0006-3525 SN - 1097-0282 VL - 103 IS - 2 SP - 109 EP - 122 PB - Wiley-Blackwell CY - Hoboken ER -