title: Entropy contribution toward micelle-driven deintercalation of drug-DNA complex.
abstract: Micelle-assisted "deintercalation" of intercalated drug/mutagen molecules from DNA is a well-established phenomenon; however, the driving energy cost for such a process is still not properly understood. In the present contribution, we have estimated the various energetic parameters for the SDS micelle-assisted deintercalation of a model DNA intercalator phenosafranine (PSF) using isothermal titration calorimetry (ITC) measurement. Both steady-state and picosecond-resolved fluorescence measurements provide strong evidence for the relocation of PSF molecules from the DNA interior to the micellar interface at an SDS concentration above cmc. The overall deintercalation process has been found to be enthalpy-wise forbidden (endothermic); however, it is strongly favored by a high positive entropy change, which can be correlated with the change in the associated hydration structure at the macromolecular interface.
authors.affiliation: Unit for Nano Science & Technology Department of Chemical Biological and Macromolecular Sciences S.N. Bose National Centre for Basic Sciences Block JD, Sector III, Salt Lake, Kolkata 700098, INDIA.
authors.forename: Animesh
authors.initials: A
authors.lastname: Patra
authors.forename: Soumitra
authors.initials: S
authors.lastname: Hazra
authors.forename: Gopinatha Suresh
authors.initials: GS
authors.lastname: Kumar
authors.forename: Rajib Kumar
authors.initials: RK
authors.lastname: Mitra
mesh_terms: D002151:Calorimetry; D004247:DNA / Q000737:chemistry*; D019277:Entropy; D008823:Micelles; D008958:Models, Molecular; D015394:Molecular Structure; D010619:Phenazines / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*
chemical_list: D008823:Micelles; D010619:Phenazines; D012967:Sodium Dodecyl Sulfate; C011977:phenosafranine; D004247:DNA