Fig 1.
Structures of (A) nogalamycin and (B) daunomycin.
Fig 2.
AFM topographs of DNA-nogalamycin complex after incubation for (A) 1 h, (B) 6 h, (C) 12 h, (D) 18 h, (E) 36 h and (F) 48 h.
DNAconc: 1.7 μg.ml-1. Scale bar: 100 nm. Z-ranges: (A) 0–0.7 nm, (B) 0–0.8 nm, (C) 0–1.4 nm, (D) 0–0.6 nm, (E) 0–0.8 nm and (F) 0–0.8 nm.
Fig 3.
AFM topographs of DNA-daunomycin complex after incubation for (A) 1 h, (B) 18 h, (C) 36 h and (D) 48 h.
DNAconc: 1.7 μg.ml-1. Scale bar: 100 nm. Z-ranges: (A) 0–1.2 nm, (B) 0–0.9 nm, (C) 0–0.8 nm and (D) 0–1.2 nm.
Fig 4.
AFM force-extension trace for 692 bp dsDNA molecule.
The red curve is the elasticity fit (well-fit to the high force ssDNA elasticity region) according to the modified FJC model having contour length (L) = 218 nm, Kuhn segment length (b) = 0.52 nm, molecular stretch modulus (S) = 800 pN at T = 25.4°C.
Fig 5.
AFM force-extension traces for nogalamycin-treated dsDNA molecules, for dsDNA:drug molar ratio (1:10) after (A) 1 h and (B) 48 h incubation; for the molar ratio (1:26) after (C) 1 h and (D) 48 h incubation; and for the molar ratio 1:40 after (E) 1 h and (F) 48 h incubation.
The red curves are the elasticity fits (well-fit to the high force ssDNA elasticity regions) according to the modified FJC model.
Fig 6.
AFM force-extension traces for daunomycin-treated dsDNA molecules, for the dsDNA:drug molar ratio (1:10) after (A) 1 h and (B) 48 h incubation; and for the molar ratio (1:26) after (C) 1 h and (D) 48 h incubation.
The red curves are the elasticity fits (well-fit to the high force ssDNA elasticity regions) according to the modified FJC model.
Fig 7.
Changes in contour length of 692 bp dsDNA incubated with nogalamycin (open square) and daunomycin (filled circle) with time.