Dresden 2006 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 40: Poster Session II
AKB 40.40: Poster
Mittwoch, 29. März 2006, 16:30–19:30, P3
DNA Melting in Aggregates: Impeded or Facilitated? — •Andrey Cherstvy1 and Alexei A. Kornyshev2 — 1Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden, Germany — 2Department of Chemistry,Faculty of Physical Sciences, Imperial College London, SW7 2AZ, London, United Kingdom
How does DNA melt in columnar aggregate relative to its melting in diluted solution? Is the melting temperature increased or decreased with the aggregate density? Have DNA-DNA interactions, predominantly of electrostatic nature, an effect on the character of the melting transition? In attempt to answer these questions, we have incorporated the theory of electrostatic interactions between DNA duplexes [1,2] into the simplest model of DNA melting. The analysis shows that the effect of aggregate density is very different for aggregates built of homologous (or identical) DNA fragments relative to the case of DNA with random base pair sequences. The putative attraction between homologous DNA helices hampers their melting and increases the melting temperature and can even dramatically change the character of the transition [3]. In the aggregate of nonhomologous DNAs, the pattern of electrostatic interactions is more complicated, and their effect could be opposite; in some cases we may even expect electrostatically induced melting [3]. These findings define new directions for melting experiments in dense DNA assemblies.
[1] A. A. Kornyshev and S. Leikin, J. Chem. Phys., 107 3656 (1997). [2] A. G. Cherstvy, A. A. Kornyshev, and S. Leikin, J. Phys. Chem. B, 106, 13362 (2002); ibid., 108, 6508 (2004). [3] A. G. Cherstvy and A. A. Kornyshev, J. Phys. Chem. B, 109, 13024(2005).