Study of Fluorescent Properties of Methylene Blue Complexes with Ribo- and Deoxyribo-Polynucleotides

A study of the fluorescent properties of MB complexes with ss-poly(dA), poly(rU), poly(rA), and poly(dT), as well as hybrid ds-structures poly(rA)-poly(dT) and poly(dA)-poly(rU), was carried out. Based on changes in fluorescence and absorption spectra, it was revealed that this ligand exhibits unequal affinity for homopolynucleotide sequences. Particularly, it was found that MS binds to poly(rA) with pronounced specificity, compared to ss-poly(dA), poly(rU), and poly(dT). The difference was also obtained for the interaction of MB with hybrid ds-polynucleotides poly(rA)-poly(dT) and poly(dA)-poly(rU).