TABLE 1.

Molecular parameters for DNA-ligand complexes

Complex	Binding mode	Molecule length at 40 pN	WLC contour length	WLC persistence length	Overstretching transition
Free dsDNA	–	16.4 μm	16.0 μm	40.0 nm	62–65 pN at 18–27 μm
Distamycin-A	Minor groove	16.7 μm	16.3 μm	26.7 nm	70–85 pN at 18–27 μm
α-Helical peptide	Major groove	17.1 μm	16.5 μm	29.4 nm	80–85 pN at 22–27 μm; crossover at 17–22 μm
Ethidium bromide	Intercalating	22.5 μm	20.4 μm	20.7 nm	No transition
YO-1	Intercalating	23.2 μm	19.8 μm	29.2 nm	No transition
Daunomycin	Intercalating	20.9 μm	19.8 μm	28.1 nm	No transition
YOYO-1	Bisintercalating	23.5 μm	21.8 μm	11.8 nm	No transition

Molecular parameters extracted from worm-like-chain model fit of experimental data of free double-stranded λ-DNA and dsDNA complexed with distamycin-A, α-helical peptide Ac-(Leu-Ala-Arg-Leu)₃-NH-linker, ethidium bromide, YO-1, daunomycin, and YOYO-1. The concentration of each binding ligand was set to 1 μM, respectively.