SOME FEATURES OF CIRCULAR-DICHROISM SPECT RA OF LIQUID-CRYSTALLINE DISPERSIONS OF DOUBLE-STRANDED DNA-MOLECULES AND DNA COMPLEXES WITH STAINED COMPOUNDS

The circular dichroism spectra of liquid-crystalline dispersions forme d of double-stranded DNA molecules were calculated. It was found that the amplitude and sing of the anomalous band in these spectra in the r egion of absorption of nitrous bases depend on the size of dispersed p articles, the pitch of their cholesterol helix and the sign of its spa tial winding. The theoretical calculations are compared with experimen tal data characterizing the anomalous optical properties of liquid-cry stalline DNA dispersions and synthetic polynucleotides formed as a res ult of phase elimination in aqueous salt solutions of polyethyleneglyc ol. The theoretically calculated circular dichroism spectra of liquid- crystalline DNA dispersions agree with the circular dichroism spectra of these dispersions observed experimentally.