title: FTIR and circular dichroism spectroscopic study of interaction of 5-fluorouracil with DNA.
abstract: 5-Fluorouracil (5FU) is an anticancer chemotherapeutic drug which exerts cytotoxic effect by inhibiting cellular DNA replication. In the present study, we explore the binding of 5FU with DNA and resulting structural and conformational changes on DNA duplex. UV-visible, Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopic techniques were employed to explore these interactions. A constant concentration of calf thymus DNA was incubated with varying concentrations of 5FU. UV-visible and FTIR spectroscopic results revealed that intercalation is the primary mode of interaction between 5FU and nitrogenous bases of the nucleic acid. The binding constant was found to be 9.7×10(4); which is indicative of moderate type of interaction between 5FU and DNA duplex. It was also observed that 5FU intercalates slightly more between AT base pairs compared to GC pairs. FTIR and circular dichroism spectroscopic results revealed that 5FU disturbs native B-conformation of DNA though, DNA remains in its B conformation even at higher concentrations of 5FU.
authors.affiliation: Quantum Optics and Photon Physics, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110 012, India.
authors.forename: Deepak K
authors.initials: DK
authors.lastname: Jangir
authors.forename: Sonika
authors.initials: S
authors.lastname: Charak
authors.forename: Ranjana
authors.initials: R
authors.lastname: Mehrotra
authors.forename: Suman
authors.initials: S
authors.lastname: Kundu
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D005472:Fluorouracil / Q000378:metabolism* / Q000494:pharmacology; D009690:Nucleic Acid Conformation / Q000187:drug effects; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D004247:DNA; D005472:Fluorouracil