Biopolymers and cell. 1992. 8 (1): 73 - 78

ZOZULYA V. N., VOLOSHIN I. M., FYODOROV V. F., BLAGOI Yu. P.

Quinacrine Interaction With Single-Stranded Polynucleotides From the Laser Polarized Fluorescence Data

Summary

    The interaction of quinacrine with single-stranded polynucleotides poly (A) and poly(U) in aqueous soluttions at neutral pH is studied hy the laser polarized fluo¬rescence method. At small polymer-dye ratios, P/D, and low ionic strength guinacrine molecule aggregation, due to cooperative binding to the polyanionic matrix, followed by chromophore stacking, predominates. Aggregation is characterized by hypochromism of the absorption spectra and by almost complete fluorescence quenching. At high P/D values the stacks of dye molecules dissociate, and its chromophores stack with base rings and change its optical properties which is characteristic of intercalation into double-stranded DNA. The quantity analysis of competition of two complex formation types was made using the obtained data and the theories proposed by Schwarz and Nechipurenko.