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Elsamicin A binding to DNA. A comparative thermodynamic characterization
Author(s) -
Barceló Francisca,
Portugal José
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.08.063
Subject(s) - isothermal titration calorimetry , chemistry , dna , disaccharide , intercalation (chemistry) , molecule , stereochemistry , moiety , crystallography , chromophore , titration , organic chemistry , biochemistry
The antitumor drug elsamicin A contains a coumarin‐related chartarin chromophore that intercalates into DNA. It differs from other related molecules in its disaccharide moiety, which bears an amino sugar. Its binding to DNA was analyzed using isothermal titration calorimetry and UV thermal denaturation, and characterized thermodynamically. For the association of elsamicin A with DNA we found ΔG ∘ =−8.6 kcal mol −1 , ΔH=−10.4 kcal mol −1 , ΔS=−6.1 cal mol −1 K −1 , and K obs =2.8(±0.2)×10 6 M −1 at 20 °C in 18 mM Na + . The contributions to the free energy of binding that lead to the DNA–elsamicin complex are compared with the binding to DNA of chartreusin, another chartarin‐containing drug. The results are discussed in terms of the contributions of the disaccharide moieties into the strength of binding.