title: The binding of ethidium bromide with DNA: interaction with single- and double-stranded structures.
abstract: The pH-induced helix-coil transition of DNA and its complexes with EtBr is carried out at acidic pH in a wide interval of change of concentration ratio of EtBr/DNA. The binding isotherms of EtBr on double and single-stranded DNA at pH = 7.0 and pH = 3.0 (t = 25(o)C) are obtained by absorption and fluorimetric methods. Binding constants (K) and number of bases (n), corresponding to one binding site were determined. Non fluorescent "strong" complex with ds-DNA at pH = 7.0 and t = 25(o)C as well as "strong" and "weak" complexes with ss-DNA at pH = 3.0 and t = 25(o)C are revealed.
authors.affiliation: Biophysics Department of the Biological, Faculty of Yerevan State University, 375025 Yerevan, Aleck Manoogian St. 1, Armenia.
authors.forename: P O
authors.initials: PO
authors.lastname: Vardevanyan
authors.forename: A P
authors.initials: AP
authors.lastname: Antonyan
authors.forename: M A
authors.initials: MA
authors.lastname: Parsadanyan
authors.forename: H G
authors.initials: HG
authors.lastname: Davtyan
authors.forename: A T
authors.initials: AT
authors.lastname: Karapetyan
mesh_terms: D000818:Animals; D002417:Cattle; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000378:metabolism*; D004996:Ethidium / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation; D013050:Spectrometry, Fluorescence
chemical_list: D004277:DNA, Single-Stranded; C029154:3,8-diamino-6-phenyl-phenanthridine; D004247:DNA; D004996:Ethidium