New optical evidence of the cholesteric packing of DNA molecules in “re-entrant” phase

Abstract

The CD spectra of dispersion particles with the “re-entrant” packing of ds DNA have been compared to the CD spectra of particles with the cholesteric ordering of these molecules.The intercalation of daunomycin (DAU) between base pairs of DNA leads to an appearance of new additional band in the CD spectra. The linking of DNA in the single particles by (DAU-copper) nanobridges transforms the “liquid-like” structures of the both particles into the “rigid” state. These effects prove the existence of the cholesteric structure in “re-entrant” DNA phase.