01981nas a2200169   4500008004100000022001400041245013500055210006900190260007100259300001400330490000800344520127300352100001801625700002401643700001801667856012601685       2016                        eng d  a1520-610600aInfluence of ionic liquids on thermodynamics of small molecule DNA interaction: the binding of ethidium bromide to calf thymus DNA0 aInfluence of ionic liquids on thermodynamics of small molecule D  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR  a2691-27000 v1203 a<p>Ionic liquids (ILs) are salts with poor ionic coordination, resultantly remaining in liquid state below 100 degrees C and some may retain liquid state even at room temperature. ILs are known to provide a conducive environment for many biological enzymatic reactions, but their interaction with biomacromolecules are poorly understood. In the present study, we investigate the effect of various ionic liquids on DNA small molecule interaction using calf thymus DNA (ctDNA) ethidium bromide (EB) as a model system. The effect of various ionic liquids on these interactions is studied by an array of techniques such as circular dichroism (CD), UV melting, fluorescence exclusion and isothermal titration calorimetry. Interestingly, we observed that presence of IL increased the stability of ctDNA without altering its structure. The binding affinities Kbs for EB binding to ctDNA in the presence of 300 mM ILs are about half order of magnitude smaller than the Kbs in absence of ILs and correspond to a less favorable free energy. We noted that, when adjusted to corresponding buffer condition, the unfavorable shift in AG of ctDNA-EB interaction is attributed to decreased entropy in the case of ILs, whereas the same effect by NaCI was due to increased enthalpy.</p>1 aMishra, Arpit1 aEkka, Mary, Krishna1 aMaiti, Souvik  uhttps://library.ncl.res.in/content/influence-ionic-liquids-thermodynamics-small-molecule-dna-interaction-binding-ethidium