Figure 2.

(A) Mean forces versus separation for the two orientations derived from the numerical derivative of the PMFs computed for orientation 1 (solid) and 2 (dashed). Insets (in both panels A and B) depict the two possible mechanisms of DNA condensation. Arrows indicate the direction of pulling force. The relative detachment force felt by the dendrimer will depend on the structure of the DNA-dendrimer complex. (B) Experimental single-molecule force-extension curves (blue, data from (14)) and theoretical curve (black) computed for an entire DNA molecule with N = 300 contacts, using the parameters derived from the umbrella sampling free energy calculations for an individual dendrimer DNA contact (see text). Experimental curve for naked DNA and a fitted EWLC (see Eq. 1) are shown in red and black dotted curves, respectively.