title: Intercalating fluorescence dye YOYO-1 prevents the folding transition in giant duplex DNA.
abstract: Recently, it has become clear that with the addition of polyamines, giant DNA molecules of size greater than 10 kbp exhibit all-or-none switching between elongated coil and folded compact states. Here the effects of the intercalating fluorescent labeling dye, YOYO-1, and the minor-groove binding fluorescent labeling dye, DAPI, on the folding transition of single giant T4 DNA (166 kbp) induced by spermidine(3+) were examined, by use of the experimental technique of single molecular chain observation with fluorescence microscopy. It is found that the intercalating dye, YOYO-1, markedly prevents the folding transition, whereas the minor-groove binding dye, DAPI, exhibits negligible effect on the folding transition. This action of YOYO-1 is discussed in relation to the biological effect of intercalators.
authors.affiliation: Department of Physics, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yoshinaga
authors.forename: T
authors.initials: T
authors.lastname: Akitaya
authors.forename: K
authors.initials: K
authors.lastname: Yoshikawa
mesh_terms: D001583:Benzoxazoles / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry; D007364:Intercalating Agents / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D017510:Protein Folding; D011806:Quinolinium Compounds / Q000737:chemistry*; D013095:Spermidine / Q000737:chemistry
chemical_list: D001583:Benzoxazoles; D005456:Fluorescent Dyes; D007211:Indoles; D007364:Intercalating Agents; D011806:Quinolinium Compounds; C075296:1,1'-((4,4,7,7-tetramethyl)-4,7-diazaundecamethylene)bis-4-(3-methyl-2,3-dihydro(benzo-1,3-oxazole)-2-methylidene)quinolinium; C007293:DAPI; D004247:DNA; D013095:Spermidine