Biopolymers and cell. 2001; 17 (3): 242 - 248

Interaction of cyanine dyes with nucleic acids. 22. Spectral-luminescent properties of monomethyne pyrylium and pyrymidinium cyanines and their DNA-complexes

S. S. Lukashov, G. O. Kachkovskyy, M. Yu. Losytskyy, S. M. Yarmoluk,

We have obtained a number of pairs of monomethyne cyanines, dyes of each pair having similar structure and contrary direction of electric dipole moment, and investigated the spectral-luminescent properties of these dyes in free state and in the presence of double-stranded DMA. The change in values of the dyes Stockes shifts under the interaction with DMA is the evidence for the location of the dyes within DMA complexes in dipole medium, that confirms the «half-intercalation» interaction model. Considering the changes of the dyes Stockes shifts under the interaction with DNA as the manifestation of changes in electronic asymmetry of these dyes, we made an assumption about the location of each dye inside the DNA. It has been concluded, that the dye molecule orientation in the DNA-complex is defined by the dye geometry, its dipole moment direction being of minor importance.