Persistence length of DNA

The (bending) persistence length of DNA, which is proportional to its bending rigidity, has been extensively studied for well over two decades, usually via its effect on the overall dimensions of the DNA coil. This work... 

All this leads to the question of how DNA affects nucleosomal stability at the molecular level. DNA bendability has been repeatedly put forward as a candidate to play an important role [280-282]. This property is related to the persistence length of DNA [283]. A study on the characterization of nucleosomes reconstituted onto methylated DNA [poly(dG-m dC) poly (dG-m dC)] [284] provides support to this hypothesis. Poly(dG-m dC) poly (dG-m dQ DNA can be induced to change from its B to its Z conformation in the presence of millimolar amounts of divalent ions [285] such as MgCl2. The persistence length of poly(dG-m dC) poly (dG-m dC) in the Z form in high salt was found to be 208 nm (ca. 612 bp) [286], a value much lower than that of the same polymer in the B form (93.8 nm, 276 bp) at... 

Substrate-dependent (the persistence length of DNA on amino-terminated mica is approximately half compared to bare mica)... 

Nature produces the stiffest worm-like chains the long persistence length of DNA (Xp = 0.053 ixm) is short compared to that of F-actin filaments, Xp 17 /xm (Ott et al. 1993) the latter are components of the cellular cytoskeleton. Self-assembled cellular microtubules are even stiffer than this, with Xp on the order of millimeters ... 

Hagerman PJ. Polyelectrolyte contribution to the persistence length of DNA. Biopolymers 1981 20 251-268. 

FIG. 1 Plot of free energy of polyvalent counterion-mediated interaction between two rods as a function of the angle between the rods for different rod separations, R (in units of the monomer size b). The two rods are parallel at 6 = 0. We then tilt one rod with respect to the other around the axis of separation between the two rods to a nonzero angle 0. The minimum at 6 = 0 that appears for short separations arises from the polyvalent counterion-mediated attraction. The minimum at 6 = 90° (which is stable at large separations and metastable at small separations) arises from the repulsion due to the net charge on the rods. For this calculation, T = 300 K, e = 80, and Z = 2. In addition, the length of the rods was taken to be 500 A (the persistence length of DNA). (From Ref. 47.)... 

The persistence length of DNA restriction fragments (64-900 base pairs, bp) is approximately 50-60 nm, dependent on the salt concentration in the range 1 mM-2 mM NaCl. 

J. Bednar, P. Furrer, V. Katritch, A. Z. Stasiak, J. Dubochet, and A. Stasiak, /. Molec. Biol., 254, 579 (1995). Determination of DNA Persistence Length by Cryo-Electron Microscopy. Separation of the Static and Dynamic Contributions to the Apparent Persistence Length of DNA. 

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