title: DNA condensation monitoring after interaction with hoechst 33258 by atomic force microscopy and fluorescence spectroscopy.
abstract: DNA condensation was only observed after the addition of Hoechst 33258 (H33258) among various types of DNA binding molecules. The morphological structural change of DNA was found to depend on the H33258 concentration. On comparison of fluorescence spectrum measurements with AFM observation, it was found that fluorescence quenching of DNA-H33258 complexes occurred after DNA condensation. Additionally, we showed that DNA condensation by H33258 was independent of sequence selectivity or binding style using two types of polynucleotides, i.e. poly(dA-dT).poly(dA-dT) and poly(dG-dC).poly(dG-dC). Moreover, it was concluded that the condensation was caused by a strong hydrophobic interaction, because the dissolution of condensed DNA into its native form on dimethyl sulfoxide (DMSO) treatment was observed. This study is the first report, which defines the DNA condensation mechanism of H33258, showing the correlation between the single molecule scale morphology seen on AFM observation and the bulky scale morphology observed on fluorescence spectroscopy.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Tatsunokuchi, Ishikawa 923-1292, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Saito
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Iwabuchi
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Morita
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Takamura
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tamiya
mesh_terms: D006690:Bisbenzimidazole / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism*; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D011067:Poly dA-dT / Q000378:metabolism; D011089:Polydeoxyribonucleotides / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D004279:DNA, Viral; D005456:Fluorescent Dyes; D011089:Polydeoxyribonucleotides; D011067:Poly dA-dT; C019530:poly(dC-dG); D006690:Bisbenzimidazole; D004121:Dimethyl Sulfoxide