Disorder of DNA Structure in Quasinematic Layers of “Re-entrant” Twisted Phases

Abstract

The CD spectra of double-stranded (ds) DNA dispersion particles with the "re-entrant" cholesteric structures formed in poly(ethyleneglycol)-containing solutions are compared. The high osmotic pressure of the solvent results in the dense packing DNA molecules and alteration of their secondary structure as well as a disorder of molecules in quasinematic layers of dispersion particles. Under these conditions, it is impossible to connect the adjacent ds DNA molecules by specific cross-links (nanobridges).