Biopolymers and cell. 1998; 14 (1): 54 - 61

Stabilization of duplex and triplex complexes of oligothymidylate by covalently linked imidazophenazine glycoside

V. N. Zozulya, Yu. P. Blagoi, I. Y. Dubey, O. D. Fedoryak, A. S. Shcherbakova, D. M. Fedoryak

Decathymidylate containing nucleoside derivative of imidazophe¬nazine (Pzn) at the J'-end was synthesized. The effect of dye covalent attachment on the formation of complementary complexes of (dT)[0, namely duplex with (dA)ts and triplex with (dA)ts and poly(dA)-poly(dT), was studied in buffer solutions of neutral pH at ionic strength u-0,1 and 1 M. Thermal denaturation method using absorption and fluorescence spectroscopy was employed. It has been shown that Pzn residue strongly stabilized duplex and triplex complexes by dye chromophore intercalation into dA and dA-dT sequences. Melting point of complexes increased for 10—12 °C for duplex and 15—20 'C for triplex structures. Stabilizing effect of