Viewing of Complex Molecules of Ethidium Bromide and Plasmid DNA in Solution by Atomic Force Microscopy

Autor: Masamichi Tsuboi, Shunji Katsumata, Toschitake Iwamoto, Kuniharu Utsuno
Rok vydání: 2001
Předmět:
Zdroj: Chemical and Pharmaceutical Bulletin. 49:413-417
ISSN: 1347-5223
0009-2363
DOI: 10.1248/cpb.49.413
Popis: 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.
Databáze: OpenAIRE