title: Interaction of coumarin with calf thymus DNA: deciphering the mode of binding by in vitro studies.
abstract: DNA is the major target for a wide range of therapeutic substances. Thus, there has been considerable interest in the binding studies of small molecules with DNA. Interaction between small molecules and DNA provides a structural guideline in rational drug designing and in the synthesis of new and improved drugs with enhanced selective activity and greater clinical efficacy. Plant derived polyphenolic compounds have a large number of biological and pharmacological properties. Coumarin is a polyphenolic compound which has been extensively studied for its diverse pharmacological properties. However, its mode of interaction with DNA has not been elucidated. In the present study, we have attempted to ascertain the mode of binding of coumarin with calf thymus DNA (Ct-DNA) through various biophysical techniques. Analysis of UV-visible absorbance spectra and fluorescence spectra indicates the formation of complex between coumarin and Ct-DNA. Several other experiments such as effect of ionic strength, iodide induced quenching, competitive binding assay with ethidium bromide, acridine orange and Hoechst 33258 reflected that coumarin possibly binds to the minor groove of the Ct-DNA. These observations were further supported by CD spectral analysis, viscosity measurements, DNA melting studies and in silico molecular docking.
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, A.M. University, Aligarh, U.P. 202002, India.
authors.forename: Tarique
authors.initials: T
authors.lastname: Sarwar
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, A.M. University, Aligarh, U.P. 202002, India.
authors.forename: Sayeed Ur
authors.initials: SU
authors.lastname: Rehman
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, A.M. University, Aligarh, U.P. 202002, India.
authors.forename: Mohammed Amir
authors.initials: MA
authors.lastname: Husain
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, A.M. University, Aligarh, U.P. 202002, India.
authors.forename: Hassan Mubarak
authors.initials: HM
authors.lastname: Ishqi
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, A.M. University, Aligarh, U.P. 202002, India. Electronic address: tabish.bcmlab@gmail.com.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Tabish
mesh_terms: D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D003374:Coumarins / Q000737:chemistry* / Q000378:metabolism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009994:Osmolar Concentration; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D014783:Viscosity
chemical_list: D003374:Coumarins; D004247:DNA; C427203:calf thymus DNA; C030123:coumarin
keywords: Coumarin; DNA binding; Docking