Thermodynamic Study of Rhodamine 123-Calf Thymus DNA Interaction: Determination of Calorimetric Enthalpy by Optical Melting Study

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• 作者：Abdulla Al Masum ; Maharudra Chakraborty ; Prateek Pandya ; Umesh Chandra Halder ; Md. Maidul Islam ; Subrata Mukhopadhyay
• 刊名：Journal of Physical Chemistry B
• 出版年：2014
• 出版时间：November 20, 2014
• 年：2014
• 卷：118
• 期：46
• 页码：13151-13161
• 全文大小：490K
• ISSN：1520-5207

文摘

In this paper, the interaction of rhodamine123 (R123) with calf thymus DNA has been studied using molecular modeling and other biophysical methods like UV鈥搗is spectroscopy, fluoremetry, optical melting, isothermal titration calorimetry, and circular dichroic studies. Results showed that the binding energy is about 鈭? to 鈭? kcal/mol, and the binding process is favored by both negative enthalpy change and positive entropy change. A new method to determine different thermodynamic properties like calorimetric enthalpy and heat capacity change has been introduced in this paper. The obtained data has been crossed-checked by other methods. After dissecting the free-energy contribution, it was observed that the binding was favored by both negative hydrophobic free energy and negative molecular free energy which compensated for the positive free energies due to the conformational change loss of rotational and transitional freedom of the DNA helix.