Binding of Hoechst 33258 and its Derivatives to DNA

Abstract

In the present work, we employed UV-VIS spectroscopy, fluorescence methods, and circular dichroism spectroscopy (CD) to study the interaction of dye Hoechst 33258, Hoechst 33342, and their derivatives to poly[d(AT)].poly[d(AT)], poly(dA).poly(dT), and DNA dodecamer with the sequence 5'-CGTATATATACG-3'. We identified three types of complexes formed by Hoechst 33258, Hoechst 33342, and methylproamine with DNA, corresponding to the binding of each drug in monomer, dimer, and tetramer forms. In a dimer complex, two dye molecules are sandwiched in the same place of the minor DNA groove. Our data show that Hoechst 33258, Hoechst 33342, and methylproamine also form complexes of the third type that reflects binding of dye associates (probably tetramers) to DNA. Substitution of a hydrogen atom in the ortho position of the phenyl ring by a methyl group has a little effect on binding of monomers to DNA. However it reduces strength of binding of tetramers to DNA. In contrast, a Hoechst derivative containing the ortho-isopropyl group in the phenyl ring exhibits a low affinity to poly(dA).poly(dT) and poly[d(AT)].poly[d(AT)] and binds to DNA only in the monomer form. This can be attributed to a sterical hindrance caused by the ortho-isopropyl group for side-by-side accommodation of two dye molecules in the minor groove. Our experiments show that mode of binding of Hoechst 33258 derivatives and their affinity for DNA depend on substituents in the ortho position of the phenyl ring of the dye molecule. A statistical mechanical treatment of binding of Hoechst 33258 and its derivatives to a polynucleotide lattice is described and used for determination of binding parameters of Hoechst 33258 and its derivatives to poly[d(AT)].poly[d(AT)] and poly(dA).poly(dT).

Electrochemical and Spectroscopic Studies on the Interaction of Gatifloxacin, Moxifloxacin and Sparfloxacin with DNA and Their Analytical Applications

“…The values of binding constants have been determined to be 3228, 2596 and 2857 M À1 for gatifloxacin, moxifloxacin and sparfloxacin, respectively. The values of K f described in the literature for intercalating molecules are at least two orders of magnitude higher than those obtained for the FQs ligands [40][41][42]. Similar value for ciprofloxacin was reported by spectroscopic and hydrodynamic techniques [28] and for levofloxacin [35] with DNA by using cyclic voltammetry at GCE.…”

Molecular Aspects of the Interaction of Hoechst-33258 with GC-Rich Promoter Region of c-met

“…Therefore, in the present study, Hoechst concentration was in low range where linearity was maintained (see the Material and Methods section). Interestingly, Hoechst has been shown to form other types of complexes with other oligonucleotides including polyGC (Streltsov and Zhuze, 2008), polyAT, and a DNA dodecamer (5 0 -CGTATATATACG-3 0 ) (Bazhulina et al, 2009). DNA-Hoechst binding has been extensively studied using various theoretically designed DNA sequences with varying degrees of affinity.…”

“…In the titration of Hoechst with 24RY, we did not observe any effect of induced CD in the region around 350 nm. However, Hoechst shows these effects in DNA sequences containing contiguous stretches of AT or GC (Streltsov and Zhuze, 2008;Bazhulina et al, 2009). Thermodynamic parameters are remarkably changed after Hoechst binding to 24RY at a D=N mole ratio of 0.4, D DG of À10 kcal=mol, D DH of À83 kcal=mol, and D DS of À241 cal=(mol K), suggesting that Hoechst binding to 24RY is thermodynamically favorable.…”

Cell-based assays for IGF-I bioactivity measurement: overview, limitations and current trends

“…Several dyes that fluoresce when binding to nucleic acids have been used to quantify cell numbers. Such dyes include Hoechst 33258 (Bazhulina et al, 2009) and 33342 (Purschke et al, 2010), propidium iodide (Bahmani et al, 2011) and 4 0 ,6-diamidino-2-phenylindole (DAPI) (Roozbeh et al, 2008). Although these dyes present an accurate method to determine cell number, their use is often limited by their low detection sensitivity due to high background fluorescence and low extinction coefficients (Jones et al, 2001).…”