Effects of methyl substitution on DNA binding enthalpies of enantiopure Ru(phenanthroline)2dipyridophenazine2+ complexes
| Autor: | Anna K. F. Mårtensson, Per Lincoln |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010405 organic chemistry
Phenanthroline Phenazine Intercalation (chemistry) General Physics and Astronomy Cooperative binding Isothermal titration calorimetry 010402 general chemistry Ligand (biochemistry) 01 natural sciences Medicinal chemistry 0104 chemical sciences chemistry.chemical_compound Enantiopure drug chemistry Titration Physical and Theoretical Chemistry |
| Zdroj: | Physical Chemistry Chemical Physics. 20:11336-11341 |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | Isothermal titration calorimetry (ITC) has been utilized to investigate the effect of methyl substituents on the intercalating dppz ligand of the enantiomers of the parent complex Ru(phen)2dppz2+ (phen = 1,10-phenanthroline; dppz = dipyrido[3,2-a:2',3'-c]phenazine) on DNA binding thermodynamics. The methylated complexes (10-methyl-dppz and 11,12-dimethyl-dppz) have large, concentration-dependent, positive heats of dilution, and a strong endothermic background is also apparent in the ITC-profiles from titration of methylated complexes into poly(dAdT)2, which make direct comparison between complexes difficult. By augmenting a simple cooperative binding model with one equilibrium for complex self-aggregation in solution and one equilibrium for complex aggregation on saturated DNA, it was possible to find an excellent global fit to the experimental data with DNA affinity parameters restricted to be equal for all Δ-enantiomers as well as for all Λ-enantiomers. In general, enthalpic differences, compared to the unsubstituted complex, were small and less than 4 kJ mol-1, except for the heat of intercalation of Δ-10-methyl-dppz (-11,6 kJ mol-1) and Λ-11,12-dimethyl-dppz (+4.3 kJ mol-1). |
| Databáze: | OpenAIRE |
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