title: Conformational and phase transitions in DNA--photosensitive surfactant solutions: Experiment and modeling.
abstract: 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.
authors.affiliation: Faculty of Physics, Department of Molecular Biophysics, Saint Petersburg State University, Petrodvorets, Ulyanovskaya str. 1, 198504, St. Petersburg, Russia.
authors.forename: N
authors.initials: N
authors.lastname: Kasyanenko
authors.forename: L
authors.initials: L
authors.lastname: Lysyakova
authors.forename: R
authors.initials: R
authors.lastname: Ramazanov
authors.forename: A
authors.initials: A
authors.lastname: Nesterenko
authors.forename: I
authors.initials: I
authors.lastname: Yaroshevich
authors.forename: E
authors.initials: E
authors.lastname: Titov
authors.forename: G
authors.initials: G
authors.lastname: Alexeev
authors.forename: A
authors.initials: A
authors.lastname: Lezov
authors.forename: I
authors.initials: I
authors.lastname: Unksov
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D009690:Nucleic Acid Conformation; D044367:Phase Transition; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D013501:Surface-Active Agents; D004247:DNA
keywords: DNA volume and persistent length; DNA-surfactant complexes; light-induced DNA de-compaction; phase diagram