Biopolymers and cell. 1987. Volume 3. № 5. 234 - 240

M. A. Semenov, T. V. Bolbukh

THE COMPLEXING OF ETHIDIUM BROMIDE AND DNA IN MOIST FILMS AS REVEALED BY IR-SPECTROSCOPY

Summary

    IR-spectroscopy is shown to be a tool in investigating the complexing of ethidium bromide and DNA moist films. The dependence of DNA backbone frequencies and intensities of absorption bands upon water content was analyzed. It is shown that at humidities higher than 56 % the DNA helix formation is accompanied by selective intercalation of ethidium bromide from the narrow groove side. This process alters the DNA structure and leads to a dehydration of nucleic base aminogroups. It is also found that the intercalation prevents from the dipole-dipole interactions between the carbonyl guanine groups.