title: Spectroscopic study on the binding of chelerythrine with duplex poly (rA): A model of RNA intercalation.
abstract: Here we have reported a detail study on the interaction of the benzophenanthridine alkaloid chelerythrine (CHL) with double stranded polyriboadenylic acid [ds poly (rA)] by exploiting various spectroscopic techniques. The alkaloid shows high binding affinity (binding constant is 1.10×105M-1) towards the double stranded RNA as revealed from Scatchard plot. The binding was confirmed by hypochromic effect in the UV-vis spectrum of CHL, increase in fluorescence intensity of CHL and perturbations of the circular dichroism (CD) spectrum of ds poly (rA). Later fluorescence quenching, cooperative CD melting transition, viscometric and molecular modeling studies establish the fact that the alkaloid binds to the ds poly (rA) by the mechanism of intercalation. Thermodynamic parameters obtained from the isothermal titration calorimetric (ITC) study show that the binding is favoured by negative enthalpy and small positive entropy changes. This report may be a model for intercalation of small molecule like CHL to the double stranded RNA.
authors.affiliation: Department of Chemistry, Jadavpur University, Raja S.C. Mullick Road, Jadavpur, Kolkata 700 032, India. Electronic address: ankurpradhan727@gmail.com.
authors.forename: Ankur Bikash
authors.initials: AB
authors.lastname: Pradhan
authors.affiliation: Department of Chemistry, Jadavpur University, Raja S.C. Mullick Road, Jadavpur, Kolkata 700 032, India. Electronic address: s.bhuiya12@gmail.com.
authors.forename: Sutanwi
authors.initials: S
authors.lastname: Bhuiya
authors.affiliation: Department of Chemistry, Jadavpur University, Raja S.C. Mullick Road, Jadavpur, Kolkata 700 032, India. Electronic address: lucy.haque@gmail.com.
authors.forename: Lucy
authors.initials: L
authors.lastname: Haque
authors.affiliation: Department of Chemistry, Jadavpur University, Raja S.C. Mullick Road, Jadavpur, Kolkata 700 032, India. Electronic address: sumandas10@yahoo.com.
authors.forename: Suman
authors.initials: S
authors.lastname: Das
mesh_terms: D053119:Benzophenanthridines / Q000737:chemistry / Q000378:metabolism*; D062105:Molecular Docking Simulation; D009690:Nucleic Acid Conformation; D011061:Poly A / Q000737:chemistry / Q000378:metabolism*; D020871:RNA Stability; D013057:Spectrum Analysis
chemical_list: D053119:Benzophenanthridines; D011061:Poly A; C016299:chelerythrine
keywords: Double stranded poly (rA); Intercalation; Thermodynamics & molecular modeling study