Regensburg 2007 – scientific programme

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BP: Fachverband Biologische Physik

BP 16: Poster Session I

BP 16.56: Poster

Tuesday, March 27, 2007, 17:00–19:30, Poster D

Electrostatics of DNA complexes with cationic lipids — •Andrey Cherstvy — Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzerstrasse 38, D-01187 Dresden, Germany

We present exact solutions of Poisson-Boltzmann equation for several problems relevant to electrostatics (el) of DNA complexes with cationic lipids [1]. We calculate the el potential and energy for lamellar and inverted hexagonal phases, concentrating on effects of dielectric boundaries. Our results for energy of complexes is in good agreement with known numerical solutions [2]. We calculate compressibility modulus B of lamellar phase and compare it with the experimental data [3]. We suggest a new scaling relation for B as a function of DNA-DNA separation. Also, we treat charge-charge interactions across, along, and in between two low-dielectric membranes. We calculate the strength of el interactions of 1D DNA smectic layers across lipid membrane to treat DNA correlations in neighboring layers in lamellar complexes. We discuss some aspects of 2D DNA condensation and DNA-DNA attraction in DNA-lipid lamellar phase with multivalent cations. We analyze equilibrium DNA-DNA separations in condensed lamellar phase [4] and in 3D DNA condensates [5] using the theory of el interactions of DNA helical charge motifs developed recently [6-8].

[1] A.G. Cherstvy, in press. [2] D. Harries, et al., BJ 75 159 (1998). [3] T. Salditt, et al., PRE 58 889 (1998). [4] I. Koltover, et al., PNAS 97 14046 (2000). [5] E. Raspaud, et al., BJ 88, 392 (2005). [6] A.A. Kornyshev et al., PRL 82 4138 (1999). [7] A.G. Cherstvy, et al., JPCB 106 13362 (2002). [8] A.G. Cherstvy, et al., JPCB 108 6508 (2004).