title: Viewing of complex molecules of ethidium bromide and plasmid DNA in solution by atomic force microscopy.
abstract: Tertiary structure changes in plasmid DNA, induced by ethidium bromide intercalation, have been observed in aqueous solutions by the use of an atomic force microscope. A relaxed closed circular pBR322 molecule became a positively supercoiled complex on the drug binding. The supercoiling always resulted in an interwound (or a plectonemic) form, but never a solenoidal (or a toroidal) form. A quantitative analysis of the compactness of such supercoiled complexes has been carried out.
authors: High-tech Research Center, College of Science and Engineering, Iwaki Meisei University, Fukushima, Japan.
authors: K
authors: K
authors: Utsuno
authors: M
authors: M
authors: Tsuboi
authors: S
authors: S
authors: Katsumata
authors: T
authors: T
authors: Iwamoto
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure*; D004591:Electrophoresis, Polyacrylamide Gel; D004996:Ethidium / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry* / Q000648:ultrastructure*; D012996:Solutions; D013055:Spectrophotometry, Infrared
chemical_list: D012996:Solutions; D004247:DNA; D004996:Ethidium