J. Phys. IV France
Volume 12, Numéro 9, November 2002
Page(s) 215 - 220

J. Phys. IV France
12 (2002) Pr9-215
DOI: 10.1051/jp4:20020398

Inversion of DNA charge by a positive polymer via fractionalization of the polymer charge

T.T. Nguyen and B.I. Shklovskii

Theoretical Physics Institute, University of Minnesota, 116 Church St. Southeast, Minneapolis, Minnesota 55455, U.S.A.

Charge inversion of a DNA double helix by an oppositely charged flexible polyelectrolyte (PE) is widely used for gene delivery. It is considered here in terms of discrete charges of DNA. We concentrate on the worst scenario case when in the neutral state of the DNA-PE complex, each of the DNA charges is locally compensated by a PE charge and show that charge inversion exists even in this case. When an additional PE molecule is adsorbed by DNA, its charge gets fractionalized into monomer charges of defects (tails and arches) on the background of the perfectly neutralized DNA. These charges spread all over the DNA eliminating the self-energy of PE. Fractionalization leads to a substantial charge inversion of DNA.

© EDP Sciences 2002