Some Features of Surfactant Organization in DNA Solutions at Various NaCl Concentrations

Irina A Silanteva; Andrei V Komolkin; Veronika V Mamontova; Pavel N Vorontsov-Velyaminov; Svetlana Santer; Nina A Kasyanenko

doi:10.1021/acsomega.0c01850

Some Features of Surfactant Organization in DNA Solutions at Various NaCl Concentrations

ACS Omega. 2020 Jul 13;5(29):18234-18243. doi: 10.1021/acsomega.0c01850. eCollection 2020 Jul 28.

Authors

Irina A Silanteva¹, Andrei V Komolkin¹, Veronika V Mamontova¹, Pavel N Vorontsov-Velyaminov¹, Svetlana Santer², Nina A Kasyanenko¹

Affiliations

¹ Faculty of Physics, Saint Petersburg University, 7-9 Universitetskaya Embankment, Saint Petersburg 199034, Russia.
² Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam-Golm, Germany.

Abstract

The photosensitive azobenzene-containing surfactant C₄-Azo-OC₆TMAB is a promising agent for reversible DNA packaging in a solution. The simulation of the trans-isomer surfactant organization into associates in a solution with and without salt as well as its binding to DNA at different NaCl concentrations was carried out by molecular dynamics. Experimental data obtained by spectral and hydrodynamic methods were used to verify the results of simulation. It was shown that head-to-tail aggregates with close to antiparallel orientation of surfactant molecules were formed at certain NaCl and surfactant concentrations (below critical micelle concentration). Such aggregates have two positively charged ends, and therefore, they can be attracted to negatively charged DNA phosphates far located along the chain, as well as those that belong to different molecules. This contributes to the formation of intermolecular DNA-DNA contacts, and this way, the experimentally observed precipitation of DNA can be explained.