Interactions of a biocompatible water-soluble anthracenyl polymer derivative with double-stranded DNA

Abstract

We have studied the interaction of a polymeric water soluble anthracenyl derivative () with salmon testes DNA. The results from UV-Vis, fluorescence, Fourier transform infrared (FT-IR) and circular dichroism spectroscopies indicate that the groove binding process regulates the interaction between and DNA. The binding constants, calculated by absorption spectroscopy at 298, 304 and 310 K, were equal to 3.2 × 10(5) M(-1), 4.7 × 10(5) M(-1), and 6.6 × 10(5) M(-1) respectively, proving a relatively high affinity of for salmon testes DNA. Results of Hoechst 33258 displacement assays strongly support the groove binding mode of to DNA. The association stoichiometry of the :DNA adduct was found to be 1 for every 5 base pairs. FT-IR spectra, recorded at different /DNA molar ratios, indicate the involvement of the phosphate groups and adenine and thymine DNA bases in the association process. Thermodynamic results suggest that hydrophobic forces regulate the binding of with DNA without excluding some extent of involvement of van der Waals forces and hydrogen bonding arising due to surface binding between the hydrophilic polymeric arms of the ligand and the functional groups positioned on the edge of the groove. The resulting composite biomaterial could constitute a valuable candidate for future biological and/or photonic applications.

Fluorescent ZnO–Au Nanocomposite as a Probe for Elucidating Specificity in DNA Interaction

“… 64 Peaks at 1660–1665 and 1564 cm –1 are assigned to the vibration of C 4 =O of thymine and amide II of the adenine moiety, respectively. 65 The 1160 cm –1 band is considered to be due to the stretching vibrations of the sugar–phosphate backbone for B-DNA. 66 A weak band at 860 cm –1 is mainly ascribed to the C–O–P–O–C backbone vibration, which characterizes the B form of DNA.…”

Photochromic switching of the DNA helicity induced by azobenzene derivatives

“…The behavior of Azo-3N is typical for molecules intercalating between the DNA base pairs and the extent of the hypochromism is related to the strength of the intercalative interaction 41 42 43 44 . Such phenomenon can be expected in regard of the aromatic rings of the azobenzene core, which, by increasing the planarity of the system, provide a greater possibility to accept the guest-molecules inside the base pairs of DNA.…”

Probing the binding mechanism of photoresponsive azobenzene polyamine derivatives with human serum albumin

“…Dynamic quenching results from the diffusive collision of the excited uorophore and the quencher and has a marked entropic character, whereas static quenching is usually observed when the uorophore and the quencher form a stable non-uorescent ground-state adduct. [29][30][31] In order to distinguish between these two different types of mechanism we processed our data using the following equation: [29][30][31] F…”

“…These values are much higher than the maximum diffusion collisional quenching rate of various quenchers with biopolymers z2.0 Â 10 10 M À1 s À1 , unambiguously emphasizing the static nature of the quenching encountered. 21,30,31 The changes occurring in the intrinsic uorescence intensity of the protein upon complexation gave the opportunity to calculate the association constants and the number of binding sites (Table 2). In order to accomplish this task both the modied Stern-Volmer equation (eqn (2)) and the Scatchard analysis (eqn (3)) were used: 33…”

“…The effect of temperature on the equilibrium binding constant provided the possibility to elucidate the thermodynamic parameters (DH, DS and DG) involved in the interaction processes. To accomplish this goal we used the van't Hoff equation: 31,33 ln…”