Figure 3.19 48
From Reference [26]. Theoretical prediction of a DNA-membrane interaction
for three different models of a membrane. The DNA was modeled as a charged
cylinder of length L and radius r0. βΩ is the grand potential and τ is the line charge
density and h is the distance from lipid surface to center of cylinder. In the above, the
quantity plotted on the у-axis is electrostatic interaction energy between the cylinder
and the surface and the quantity plotted on the x-axis is related to the DNA-membrane
separation, (mobile)-, the model membrane is composed of three types of mobile surface
groups: negatively charged, neutral and dissociable. (N-P): membrane charges result
from dissociation as in case I, but surface ions are immobile, (homogeneous): charges
are fixed, surface ions are immobile. In all three cases, the homogeneous
surface charge density far away from the DNA is equal and corresponds to an
effective homogeneous charge density of pc= -1/4.8 nm2 ( κ^1 = 50 nm).
Xl